Yes, WireGuard was designed to fix a lot of these issues. It does change the equation quite a bit. I agree with you on that (I kind of hinted at it but didn't spell that out I suppose).

That said, WireGuard AFAIK still only works well with static IPs/becomes a PITA once dynamic IPs are in play. I think some of that is mitigated if the device being connected to has a static IP (even if the device being connected from doesn't). However, that doesn't cover a lot of self hosting use cases.

Tailscale/ZeroTier/Nebula etc do transfer some control (Nebula can actually be used with fully internal control and ZeroTier can also be used that way as well though you're going to have to put more work in with ZeroTier ... I don't know about TailScale's offering here).

Though doing things yourself also (in most cases) means transferring some level of control to a cloud/traditional server hosting provider anyways (e.g, AWS, DigitalOcean, NFO, etc).

Using something like ZeroTier can cutout a cloud provider/VPS entirely in favor of a professionally managed SAS for a lot of folks.

A lot of this just depends on who you trust -- yourself or the team running the service(s) you're relying on -- more and how much time you have to practically devote to maintenance. There's not a "one size fits all answer" but ... I think most people are better off doing SAS to form an internal mesh network and running whatever services they're interested in running inside of that network. It's a nice tradeoff.

You can still setup device firewalls, SSH key-only authorization, fail2ban, and things of that ilk as a precaution in case their networks do get compromised. These are all things you should do if you're self hosting ... but hobbyist/novices will probably stumble through them/get it wrong, which IMO is more okay in the SAS case because you've got a professional security team keeping an eye on things.