That really is an important question, no matter how much it bothers some. There are strong forces at work, including sexism/militant feminism, parish politics, partisan politics, etc.
I attend the same exact parish church I did as a kid. OF Mass was 1 priest, 2 altar boys and 1 of the sisters from the school across the street was the sacristan and 1 reader. A total of 5 people/Mass, or 35 total for 7 Masses each Sunday.
Today Mass takes 1 priest, 1 or 2 altar servers, 1 “captain” (yes, I know), 1 cantor, 2 readers and 23 EMsHC (22 if a deacon is present.) A total of 30 people/Mass or 210 (!) total for 7 Masses each Sunday.
This has spawned the “need” for lay “coordinators”, complex scheduling systems, limited training, etc., etc. It’s a mess. Try to change it though and the insiders will dig in with everything they have to maintain the status quo.
Offering communion under once species in my parish would eliminate the need for 84 EMsHC each week. 7 readers could also be eliminated…