It's worth noting that most classes got straight up boosts in Tasha's. Wizards can swap their cantrips on a daily basis. Clerics and paladins can channel to recover spells. Druids can summon familiars. Versatility is power.
Fighters got the ability to retrain every 4 levels...
Would it really have been so much if fighters could change their style on a short/long rest?
Tasha's also gives fighters out of combat uses for their maneuver dice - allowing them to add a significant amount to a check when needed.
It's a baby step, but it's huge relative to the 0 they were getting before!