I can only assume they don't actually work with the pi because if you spend just a minute looking at any reseller's inventory or even just the official website you will see they still make and sell and support boards from a decade ago.
If you're using the Pi as a microcontroller that you can run Python on, then just get the cheapest Pi that meets your needs.
If you're using the Pi for computationally expensive tasks then pay more money and get the fast one.
Personally I have a Pi 5 and it's perfect for me because I want small size but high performance. People say "just buy a real computer" but that would be higher energy and larger footprint.
The whole point of these things is that you use them for whatever you can imagine. Since different people have different imaginations it only makes sense that there's a range of different devices to suit everyone.
Raspberry Pi’s biggest strength is its form factor and low power draw.
So this is the embedded Linux usecase. And... the embedded Linux ecosystem seems kinda... hacked together? You a lot of the times get Yocto Linux which is its own can of worms because you tend to invariably get meta-vendor packages that patch everything from U-Boot to the kernel to random userspace utilities. There are better cases and it depends on how much the vendor works upstream. Sometimes the vendor doesn't even bother with maintaining the meta layer and it ends up getting into a "maintained mostly by one guy in Nebraska" scenario
Some other vendors seem to take U-Boot and a copy of the Ubuntu LTS sources from 10 years ago and hacked it until it was possible to get a root shell without the thing going into a kernel panic then put the resulting image on a Google Drive or FTP server somewhere but didn't go much further than that
What ends up being is that there is like a U-Boot and Linux kernel variant for either each different SBC (or sometimes vendor thereof) duck taped together. Support, even for the peripherals included, can be spotty at best, and there are many times where you have to patch the kernel or userspace to get it to work right. I've seen boards which run the weirdest stuff, ones whose kernel patches run into the megabytes with poor (if any) documentation, boards which apparently don't want to run anything but Android, etc. There are certainly vendors that work well and upstream and make everything nice and easy but they tend to be rarer and/or more expensive
Compared that with the Pis and the difference is night and day enough that the raw specs matter less. Yes RasPi has their own kernel fork, but iirc they do work a bit upstream and the versions maintained are like 6.12 and not like 5 (which I've seen). They are also relatively easy to procure where more specialized vendors tend to be... less so. Flashing them is pretty simple and if you want to create your own image you can do that as well easily without Yocto or whatever. The HAT ecosystem is a nice way to add extensibility, the headers basically allow you to do a lot of ESPy type things as well (since Linux has native specific userspace support for GPIO, I2C, SPI, PWM, LED, hwmon, etc). And so on and so forth. And it all just kinda works
This in of itself, makes it a pretty decent option for industry, especially if it's like either n <= 1000 units or a relatively small part of the BOM itself. It often is very much the economically sensible option to stick a Pi in it rather than put many man hours into fixing problems that really shouldn't require me to open up menuconfig or apply a kernel patch again.
People like Geerling tend to come at it from the hobbyist or maker side of things but it does apply to the industrial side too. Yes in many cases knowing part XYZ will still be manufactured in 30 years is more important than the dev experience or some other factor is at play (power draw being another) but in a lot of cases its not (e.g. more portable code, stuff not requiring recertification) and the Pis also do have a relatively reasonable time guarantee too. It shouldn't be a bad experience to develop on these boards! But regardless, there are a lot of times that it is, and that's why I think the RasPi continues to do as well as it does.
This is also why I think, despite the price, it continues to do well in the hobbyist community. I can hook it up using the headers to anything SPI, I2C, etc, and start making it do things with very little software trouble and regardless if I want to do it in C or if I want to do it in Python
They really want to assure people that they can get a near identical replacement for years to come if they want to build a product or deploy one somewhere.
