I’m not convinced that this is a temporary issue - the mastodon servers seem to require relatively high upkeep (cost, cpu, and manual time) for relatively few users, which naturally leads to instances reducing/blocking new accounts and even just shutting down, which further exacerbates the load on other instances.
As I wrote in an earlier thread[1], this indeed is a problem. With mastodon.
But as numerous people replied, many alternatives are ready or wip. Many of them make hosting really easy. Since that thread I tried several. Gotosocial being my favorite, now.
So this too isn't fundamental. Because 'mastodon' is about much more than this one piece of software. It's a network, the fediverse. And you can easily host a near 1-1 mastodon alternative today on a cheap, VPS.
So this is temporary, and certainly not a fundamental issue.