Standup comedian is a freelance job. It's perfectly possible to be unable to perform and still be a comedian, whether due to lack of material or lack of opportunity.
It's still possible to perform while being less able to get gigs, less able to come up with good jokes, less able to make those jokes relevant, increasingly feeling the jokes are superfluous as everything seems to get at satire-level status by itself, etc - in other words while "not being able to perform" and being slowly put out of a job.