Just like the good old days.
There are quite a few servers with human players. It's an old title that hasn't been maintained in almost 20 years. It really is provided as an "as is" product.
Err, no. In the 'good old days' it played great - and on very low end systems. If you were playing it at the time you would know this.
"Great" subjective. It ran OK on my GeForce 2 MX on lower settings. I still have that machine. RTCW actually required new technology to run that gave a lot of people headaches at the time, including pixelshader. Even then, it was based on Quake 3, so surpassing that wasn't super hard if you had a relatively modern dedicated GPU.
In any case, it was a joke about the connectivity at the time, and overloading the base game with clutter. Dial-up was still common in that era. DSL was also still considered favorable. A 5-10 Mbps line was incredible in a non-business setting. At least by 2005, I remember servers downloading their custom scripts and enhanced Quake 3 callouts. RTCW was certainly well optimized, but running well on "very low end systems", especially on dail-up, was not something I remember.
This is completely ignoring that this game is running on tech that was developed in the 1990s. It can't be expected to act predictably on modern hardware.