I dislike the dipping mechanic for example and think that its silly and takes away from the verisimilitude of the world. A reason they may have implemented it is because martial classes have very few actions to perform in combat and so it gives them more actions to do and thereby opens them to becoming more tactical to play. I still don't think its a good change, but that is besides the point.
I agree that dipping is ridiculous and that you’ve probably correctly guessed their rationale. I think they’re trying to fix problems that don’t exist though because the game is incomplete or they’re not used to thinking in 5E terms. Warriors may have ‘less to do’ but some people prefer simpler characters to run. And, particularly when you get to higher levels, items can definitely give players more options. We’re constantly joking about the fighter in our Avernus campaign being the best spellcaster in the party because we’ve given him all the items with charges that he can cast from. Warriors at low levels can also get clever using items… alchemists fire, smoke grenades, oils, poisons etc. We don’t need to turn every fighter into Beric Dondarrion to make them viable.