well they (as in the writers) have keep Jessie, James, and Meowth as stouges/villians so Ash can feel accomplished that he can beat them that he can take on the world because he can defeat them. I only wish that they maybe first bring back the old TR members that we havent seen since season 2 omg like for example Domino was a interesting character with no backstory so that always keep me wondering for an answer. Then make a new TR character to add something new to the season someone is very strong trainer and physically strong that if rank would be as good as league champions that Ash wouldnt want to interfere with without help.

About the movies its just mindboggling to me that the focus is so much on Ash doing the impossible (even though i know he is the main character) still there should be limits to what he can do since he cant even defeat some of the gym leaders without trying twice and cant beat Paul.

Brock his role has definely decreased dramastically since the first couple seasons now like you said is just an annoying annoucer and talks strategy and points out weaknesses in the battle styles of Ash and Dawn. i guess he doesnt want to be much since he was a former gym leader thats how he knows it but he wants to journey around to be a nurse and follow kids.