I find that anime was more consistently high quality in terms of animation quality from about 84 up until about 91 personally, maybe up until 94, and generally 70s and early 80s anime have the strongest storyboarding. There were some major innovations in the 90s, but shows fell back on still images far more, shot composition got a bit less inventive, Shinbo is the person I can think of who really stands out who wasn't already active in the 80s, and before the OVA market collapsed they were pumping out way too many low quality ones, fewer lavishly animated films as well. When TV anime spiked in 98 quite a few of the shows looked kind of bad too. That general level of high quality we were seeing in mid-late 80s TV anime, when the market for it contracted seemed very distant by that point. Keeping a show looking good for almost 100 episodes straight like the did with Maison Ikkoku feels downright impossible for the industry to pull off at any other time.
There were some huge accomplishments and overcoming of past restrictions, in the 90s though, like Hamaji's Resurrection, but then in the 80s we had stuff like Be Invoked, Birth and Akira which did the same. A small handful of realist animators definitely reached peak skill level by the mid 90s, Ohira, Iso, Utsunomiya, Inoue, Okiura, but then Kanada school guys like Kanada and Yamashita were doing the same a decade earlier.