I kept putting microformats into my markup for years, even though I was convinced no one was using them any more. Then I discovered people had moved on to v2 in #indieweb circles and I had some catching up to do 😂
But I can personally guarantee that it'll keep working and remain available so long as I can afford the DNS and VPS fees. I can't say that about any other place I post on the internet.
Own your own space on the web. Post there. Write there. Link to it from your various accounts elsewhere. #indieweb