Personally, I think the M1 Macs are too new for other than hard-core bleeding edge people like joemike (who has expressed some frustrations about his).
As for your MBA, the only real limit to its useful life is as long as it works and is able to run the apps and access the websites you need.
You eventually won't be able to upgrade it to the newest version of macOS, but neither age nor that will necessarily make it obsolete.
