Help with Clients

For years I have been looking for an easy way for a client to basically only receive keyboard, mouse and video from a server for a user account on that server. I used dedicated dumb terminals for this to boot into server for a while, but it is not maintanable and a huge workload.

There are well known legacy methods to do this but they are a pain to maintain, with sometimes really tough server configs as I mention above.

What I want to know if anyone know of a modern way to accomplish this, e.g. the client on a barebones Linux install, ssh into his account on the server and from there-on the server interface mouse and keyboard for the user is forwarded to the client and the user can use everything on the server. The client OS has no applications installed, and no more business other than to display video and forward mouse/keyboard and sound if possible. This saves all the resources needed to maintain the clients compared to using ssh/X-applications on a client.

I really dont want amateurish swimmy vnc and such outdated garbage. It needs be fast and snappy and directly from server indistinguishable from a normal linux system.

Sunn used to do this with impunity.

Anything new like this exists for Linux that is easy to configure?
Google searches just gives unrelated garbage from mousepushers.