I've been playing bass since before many here were born, and for a year, just before Covid, I took lessons from a West End player. I told him he probably wasn't going to shift me out of my rut, but could he make it wider.
He didn't teach me anything I didn't already know but he taught me how to use it in different ways. That improved my fretboard skills, improved my fluency and made me think differently. . . . took the blinkers off.
Anyone who thinks lessons can't teach them anything, or lessons won't improve how they play, is wrong.