> Wouldn't it be great to have a platform where they can still contribute to open-source projects during a transitional period?

Indeed it would. Things like Patreon are still usable even if you're "just" a contributor, but it'd be nice if there was one of these patron platforms that better showcased open-source contributions. GitHub Sponsors is a step in the right direction, but there's still a waitlist to be eligible for sponsorships after, what, a year?

Of course, in all likelihood, if jobs are drying up then so will such sponsorships, be it on existing platforms or entirely new ones.