I wouldn't say it's pessimistic because philosophy continues to spin off new disciplines. Linguistics and economics were considered subdomains of philosophy a century ago.

Sociology is still heavily laden with philosophy. Right now artificial intelligence is informed by things that were called "cognitive science" when they were in the philosophy department.

It may be that one day philosophy is reduced to re-treading metaphysics and ethics as insoluble problems. But we're not there yet, so I don't think it can be rightly called pessimistic just now.