IME (being a server and having siblings who served as well) we did have many different sizes of albs. Originally we attended a very small rural church where servers took individual responsibility for ensuring they wore an alb that fit - the parish had a small number of albs in different sizes; since we only had one Sunday Mass and usually only about 3 servers would serve it wasn’t a big deal. (In our whole parish I think we had about 6-8 kids who served total.) Later we started attending a larger city parish after our rural parish closed. This parish had numerous albs of different sizes and the sizes were labelled. They kept track of which servers needed which size of alb. Keep in mind that this parish had 3 weekend Masses (vigil Saturday night plus two Sunday Masses), the Knights of Columbus served Mass one weekend a month, and there were a number of servers who served each Mass. (Usually they would have 3 to a Mass and there would be 3 or 4 groups who would alternate over the course of a month for each Mass.) Having been in the sacristy I suspect they had ~30-40 albs or so.