The two main problems I ran into were 1) software support at the application layer, and 2) video driver support. There is a herculean effort on the part of package maintainers to build software for distros, and no one has been building 32 bit version of software for years, even if it is possible to build from source. There is only a very limited set of software you can use, even CLI software because so many things are built with 64 bit dependencies. Secondly, old video card drivers are being dropped from the kernel. This means all you have is basic VGA "safe-mode" level support, which isn't even fast enough to play an MPEG2. My final try was to install Debian 5, which was period correct and had support for my hardware, but the live CDs of the the time were not hybrid so the ISO could not boot from USB. I didn't have a burner so I finally gave up.
So I think these types of projects are fun for a proof of concept, but unfortunately are never going to give life to old computers.
It baffles me how usable Office 97 still. I was playing with it recently in a VM to see if it worked as well as I remembered, and it was amazing how packed with features it is considering it's nearing on thirty. There's no accounting for taste but I prefer the old Office UI to the ribbon, there's a boatload of formatting options for Word, there's 3D Word Art that hits me right in the nostalgia, Excel 97 is still very powerful and supports pretty much every feature I use regularly. It's obviously snappy on modern hardware, but I think it was snappy even in 1998.
I'm sure people can enumerate here on the newer features that have come in later editions, and I certainly do not want to diminish your experience if you find all the new stuff useful, but I was just remarkably impressed how much cool stuff was in packed into the software.
The point being made was that for many people whose lives doesn't circle around computers, their computing needs have not changed since the early 1990's, other than doing stuff on Internet nowadays.
For those people, using digital typewriter hardly requires more features than Final Writer, and for what they do with numbers in tables and a couple of automatic updated cells, something like Superplan would also be enough.
So in other words, their computer needs have changed significantly.
You can't do most modern web-related stuff on a machine from the 90s. Assuming you could get a modern browser (with a modern TLS stack, which is mandatory today) compiled on a machine from the 90s, it would be unusably slow.