A lot of the small/mini/micro form-factor systems (even ~five year old used corporate machines) are almost always the (significantly) better option at the price point. I bought a used Dell SFF system a couple of weeks ago for $119 that runs circles around the Pi in every way (16GB RAM, NVMe, real I/O, real USB, PCIe, six core i5, etc) while idling at 9 watts, which makes little difference in operating cost even in locales with the most expensive electricity in the world - especially as the Pi continues to be more power hungry and often requires a fan. The SFF system is even upgradable to 64GB of DDR4 and has a full length x16 PCIe slot and an additional x4 slot.
This machine does everything in my house, even functioning as a 2.5gb router which is already something the Raspberry Pi could never do. Add on a dozen docker containers, a VM or two, and the gap only widens. I did upgrade the RAM for $40 but the systems it replaced more than make it come out ahead on power and cost. You can still resell a Pi 4 for ~$70.
Perhaps most important - availability. There is no shortage of these systems on eBay and elsewhere (or new), there never has been and there likely never will be.
For many years the Raspberry Pi was a good default "go-to" for many applications but x86_64 has come a long way and at this point I struggle to come up with all but a few bespoke use cases for the Raspberry Pi.