The CGI was done on a shoestring budget, originally on Amigas and eventually on Dec Alphas. They were using Lightwave3D, which at the time was on the edge of affordable to students or indie producers. So it was neat seeing a tv show doing something you could do yourself on your home PC with enough patience and determination.
It's a remarkable achievement but yes, it does look rather dated sadly.
My main annoyance with B5 is how the alien designs echo human historic stereotypes. A lot of sci fi falls in this trap.
The Minbari are meditative asians. The Centari are a decaying franco-romanesque empire. The Narn are primitive and violent with dark skin and exaggerated facial features. The humans are plucky American go getters. The Vorlons are the only real original alien design, but were deliberately made a blank canvas of mystery.
Mind you in no way do I think it was malicious, just a lazy writing crutch others have used. Star Trek TNG had some pretty glaring examples of the same thing in early seasons. Star Wars patterns the Jedi after Samurai.
Even if there's a universe/plot justification for why all the alien species are humanoid variations too, I think it's a lot more interesting if the writers can come up with unique histories and cultures for the aliens.