I think 45 minutes is a trial test linked to stamina but the problem of teams with 5 excellent players and no substitute is not solved at all yet.
Again hope the effectivness of the players per minutes played will follow the age of the players, no problem till 25 years then if you wanna play 48 minutes with a 30yo player you must be penalized more than what we see right now.
1990-2022 Stalinorgel - https://www.youtube.com/watch?v=pV-Xppl6h8Et