One concern the post brings up - single point of failure. Yes, in this case, blah blah big company microsoft blah blah (I don't disagree, but..). I'm more worried about places like Paypal/Google/etc banning than the beast from Redmond.
Self hosting, it's still a single point of failure and the article arguing "mirroring", well... it allows redundancy with reads but writes?
It's an interesting take on a purist problem.
I think it’s a fair concern, e.g. forgejo is a simple directory on disk, with an option to make that into an S3 storage. It really is a no brainer to set that up for as much resilience as necessary with various degrees of “advanced” depending on your thread model and experience. The lack of a FAANG/M in the equation makes it even more palatable.
I found the banning comment to be odd. That said, all it really takes is a policy change (something that I see as far more likely in Microsoft's case) or simply a change in the underlying software (again, somewhat likely with Microsoft) for the platform to become unusable for them. Keep in mind that Dillo is a browser for those who can't on don't want to fit into the reality of the modern web.
Redundancy for read access to the source code is a concern for Dillo. Some years ago, the domain name registration lapsed, and was promptly bought by an impersonator, taking the official repository offline. If it hadn't been for people having clones of the repository, the source code and history would have been lost.
How do people find your online project and know it's you (instead of an impersonator) without relying on an authority, like GitHub accounts or domain names? It is a challenging problem with no good solution. At least now the project is alive again and more resilient than before.