I disassemble and reassemble mine about 3 times a year for a good thorough cleaning – I’ve never changed the gasket. It’s been about 6 years. Sure it’s now mostly coffee coloured like you show in the pic, no other signs of wear or breakdown at all.
I have Moka pot using friends who never clean theirs more than a rinse out and have never changed the gaskets ever. They laugh at my suggestion to take it all apart to clean even once in a while.