As much as the sound production suffers, his composition writing skills also suffer. His improvised solos are suffering because it's always the same keys, and the same drum patterns. If the drum pattern is always, "dooka dokka dooka dokka dooka dokka", with the Bassline in E, then it always warrants the same type of solo...and it's beyond stale.
He needs someone to tie him to a chair, bound and gagged, and show him all the instances in the past 20 years where he has repeated himself, be it lyrically or musically. He needs someone like a Mr. Miyagi to teach him discipline, where if he plays the same arpeggio or same linear run more than once in the same solo, the teacher whips his hand with a cane and says, "nope, you've already played that, do something else!!"