There's absolutely nothing stopping you from just using WireGuard if you want to. I don't understand the mentality of complaining about a completely separate entity offering extra features just because you don't personally have a need/want for them.
I don't get the issue with having a tight secure underlying vpn protocol, and others building on top of it to improve deployment and setup/management side of it.
Agreed. I don't think people recognize how much of a pain cert management/orchestration can be, and Tailscale's value adds like MagicDNS and managing/creating SSH keys for logging into servers are significant QoL improvements. Sure, you can do that stuff on your own, but I simply don't want to.
I do run my own Wireguard VPN at home. It’s not terrible for a few clients with a set home dyndns or static IP.
It has basically taught me how the small building blocks for Wireguard work. And how for anything remotely more difficult or multi-user I’d absolutely want something more robust handling the orchestration and management of the network. It is very hard to get right and can be very complicated to keep everything in sync. There is definitely value to what Tailscale, et al deliver.
I’m happy that I can run a simple version myself, but only after doing that can you really appreciate where the dragons be.