Well, tbh most of the Technic sets from the late '80s to the mid-'90s had fewer technical features than a transporter gang car nowadays. Not to mention the late '90s/early 2000s, with those horrible slammer cars/robothings. I was revisiting some of my childhood sets, like 8248, 8235, and 8230, and they were honestly atrocious. Comparably priced sets available today, like 42198, 42167, and 42201, are way better.
The things that changed somewhat for the worse are the flagship sets: 8480, 8479, 8880, and 8868 were more "fun" and playable, and they had B-models (but tbh, even if modern sets appear less "rebuildable" at first glance, just take a look at Rebrickable...). It's like modern sets feel less like enjoyable toys and more like cold display pieces, and there's some truth in that, but I guess it's mostly due to nostalgia.
Another issue is the overpricing of some sets, like the 1:8 scale cars, 42215, and 42175 for example, but you can find them at prices comparable to the flagship ones of the '90s adjusted for inflation. Honestly, I would have loved modern sets as a child, and I don't think I would have had a dark age if I had received something like the 42179 instead of the 6617 as a Christmas present in 2000.