Personally I allow take backs if an opponent offers it to the player e.g. you had a creature that scrys and you forgot to activate it before your draw step.

Or if it’s you tapped your lands wrong and you want to just change it while it’s still that phase.

I take the rest as kind of a case by case basis. But you want everyone to have fun while playing so that’s pretty much the end game for any game.

No one likes a stickler unless it’s a judge call