They were fine machines in the mid 201Xs but time and software has moved on.
Yes, and no.
Time has moved on, but software and the computers it runs on are - faults notwithstanding - exactly as usable now as they were then. They're not living creatures and thus decline with age. They remain exactly the same.
So yes, the things a computer can do
today may have improved - though outside internet related activity, probably not much - and in absolute terms performance continues to improve, but what people generally do with their computers doesn't change much.
That means that something like, for example, a 2014 MBP with the software bought and installed on it when it was new and for a couple of years or so at least, will be exactly as useful as it was then, doing exactly what it could do then. If the use case hasn't changed, the usability hasn't either.
And just for grins, I did an experiment, comparing a 2023 Windows PC, and a 1992 Mac Classic II. The Windows system is 8Gb RAM, 256Gb SSD, and clocked at a miserly 2.2GHz. The Mac has 10Mb RAM, a 2Gb SD card for storage, and runs at 16MHz.
An easy win for the Windows box, obviously.... except not. The Windows system and the Mac take almost exactly the same time to boot up, the Mac is slightly faster opening Word (admittedly, v5.1 rather than 2021, but it's period correct) and actually does a spellcheck on a 20-page document slightly faster too.
The point being, that a 32 year-old Mac is actually slightly faster and just as usable as a modern PC if what you want it to do is write a document. And while you would justifiably point out that this is a very basic use of a computer, and the Mac can't really do anything on the internet at all, or even get email, that doesn't detract from what it
can still do just as well as it ever could, for those who want to do exactly that. And of course given entire businesses and productive work was done then on systems just the same, including the design, typesetting and production of newspapers and magazines for example, these were not just toys.
What is happening in modern computing, is that as system performance improves, so software grows to swallow up that performance and the resources the system has. It doesn't mean it is actually better.