Nobody is "cheering" for anything here. Neither is anyone claiming they did something miraculous here. Windows' elevation system has worked without something as risky as the SUID bit for decades, for instance. Using system services to spawn root (or NTAUTHORITY\SYSTEM) tasks has been a thing since what, Windows XP? systemd-run does a bunch of really cool stuff that I could consider revolutionary if the tools all line up, but this isn't one of them.
All that's happening is that one of the systemd devs is happy to announce a sudo alternative that doesn't have the common sudo risks. No distro has announced implementing this in place of sudo, and it wouldn't make sense in the first place; sudo does stuff like LDAP that systemd-run doesn't even support, so it can't be replaced. It's taken years for Wayland to be enabled by default, I doubt we'll see distros with run0 instead of sudo this decade. It'll be available on recent distros and you can use it if you want, it's up to you.
I've never seen doas come close to taking sudo's place so I doubt this will change much. With Ubuntu and a few others having recently released a new LTS, it'll be a while before run0 will be available in distros in the first place, if it doesn't get patched out by the likes of Debian.
However, if people find run0 to be better than sudo, I don't see why they shouldn't be allowed to be happy about that. Personally, I'd rather see sudo implement a daemon/client model rather than systemd-run having an alternative argv[0], but until sudo gets better, this is the best we get.