Pope Zachary (679-752 AD), citing Pope Gelasius I (410-496 AD), explicitly condemned the practice of women and girls serving the priest during the Mass:
Pope Zachary - Codex Epistolaris Carolinus 5 (January 5, 747 AD)
5 Chapter 26 in the book of blessed Pope Gelasius' decrees concludes on these [questions]: that 'it is wrong for women to minister at the holy altar or to presume to do anything of what are reckoned to be the duties of men. Nonetheless we have heard (to our annoyance) that such great contempt for divine matters has arisen that women are being encouraged to minister at sacred altars and their sex, as unsuitable as it is, to perform all those things allotted to the service of men. However the whole guilt and blasphemy for each one of the pernicious crimes we have proscribed falls upon the priests, who either commit them, or, in failing to expose those committing them, indicate that they favor wicked excesses.'
Above, the Pope uses scathing moral language against the practice - it is called "wrong", it is said to show "great contempt for divine matters", and it is associated with "blasphemy", "pernicious crimes", and "wicked excesses".
Pope Benedict XIV (1675-1758 AD), likewise, explicitly banned women and girls from serving the priest during the Mass. He, as Pope Zachary, appealed to Pope Gelasius I (410-496 AD), and also Pope Innocent IV (1195-1254 AD), who had done the same:
Pope Benedict XIV - Allatae Sunt (1755 AD)
29 Women Assisting at Mass
Pope Gelasius in his ninth letter (chap. 26) to the bishops of Lucania condemned the evil practice which had been introduced of women serving the priest at the celebration of Mass. Since this abuse had spread to the Greeks, Innocent IV strictly forbade it in his letter to the bishop of Tusculum: "Women should not dare to serve at the altar; they should be altogether refused this ministry." We too have forbidden this practice in the same words in Our oft-repeated constitution Etsi Pastoralis, sect. 6, no. 21.
Notice that the above also uses moral language. Women serving in the Mass is called an "evil practice", and an "abuse". Consequently, it is "strictly forbidden", on those grounds, and on the grounds of tradition (two other Popes).
This was reiterated in the 1917 Code of Canon Law:
1917 Code of Canon Law - Canon 813
2 The minister serving at Mass should not be a woman unless, in the absence of a man, for a just cause, it is so arranged that the woman respond from afar and by no means approach the altar.
Notice above, that even if contingency required a woman to be an altar server, she was still forbidden to approach the altar.
This was again explicitly upheld in an instruction on the Eucharist ratified by Pope John Paul II:
Pope John Paul II - Inaestimabile Donum (1980 AD)
There are, of course, various roles that women can perform in the liturgical assembly: these include reading the Word of God and proclaiming the intentions of the Prayer of the Faithful. Women are not, however, permitted to act as altar servers.
Therefore, up until 1980, there appears to be a constant tradition of explicitly refusing women the role of serving the priest at the altar.
The Code of Canon Law was revised in 1983, and while it did not repeat the canon against female altar servers that was present in the 1917 Code, it still used to reflect the prohibition on female altar servers, in stating that lay "men" are to be considered eligible for the ministry of altar server:
1983 Code of Canon Law - Canon 230
1 Lay men whose age and talents meet the requirements prescribed by decree of the Episcopal Conference, can be given the stable ministry of lector and of acolyte, through the prescribed liturgical rite. This conferral of ministry does not, however, give them a right to sustenance or remuneration from the Church.
However in 2021, Pope Francis issued a Motu Proprio letter in which he officially amended the Code of Canon Law to allow women and girls to be altar servers, something which had already become somewhat common due to a number of smaller reforms that took place in the preceding decades:
Pope Francis - Spiritus Domini (2021 AD)
Accepting these recommendations, a doctrinal development has taken place in recent years which has highlighted how certain ministries instituted by the Church are based on the common condition of being baptized and the royal priesthood received in the Sacrament of Baptism; they are essentially distinct from the ordained ministry received in the Sacrament of Orders. A consolidated practice in the Latin Church has also confirmed, in fact, that these lay ministries, since they are based on the Sacrament of Baptism, may be entrusted to all suitable faithful, whether male or female, in accordance with what is already implicitly provided for by Canon 230 § 2.
Consequently, after having heard the opinion of the competent Dicasteries, I have decided to modify canon 230 § 1 of the Code of Canon Law. I therefore decree that Canon 230 § 1 of the Code of Canon Law shall in future have the following formulation:
"Lay persons who possess the age and qualifications established by decree of the conference of bishops can be admitted on a stable basis through the prescribed liturgical rite to the ministries of lector and acolyte. Nevertheless, the conferral of these ministries does not grant them the right to obtain support or remuneration from the Church".
Notice the cure-all of "doctrinal development" is used to excuse what is just another irreconcilable contradiction in the doctrine of two "Vicars of Christ". This will never be anything more than a dishonest excuse to pretend that contradictions and revisions in doctrine don't actually present the problem that they manifestly present to anyone who is concerned about the truth.
The modern Catholic Church expects a person to accept that until after the 1980s, the Church refused women a ministry that they were actually eligible for, because their understanding of lay ministry hadn't fully "developed". It took nearly 2,000 years to understand that women could perform that role? Really? And meanwhile, they didn't simply not do it, but rather vehemently forbade it, and called it an "evil practice"?
Cardinal John Henry Newman famously said "To be deep in history is to cease to be Protestant". In reality, for those with eyes still open to see the truth, to be deep in history is to find that the Roman Catholic Church is a manifestly false branch of Christianity, which has a mass of self-contradictory doctrine taught by those that it declares to be infallible.