Raspberry pi are really only interesting if you want to stick to the small form factor and the usually come without screens and keyboards.
EDIT: raised price from 50 to 100€ as a quick search only showed netbooks and laptop with 1 or 2GB of ram for 50€ in a 10km radius. In 2 minutes I found a Thinkpad T420 with crappy screen resolution 1366x768.
Goes doubly so for the Pi specifically, since they stayed on 32 bit armhf OSes for the longest time which have even less package support and just straight up cannot run a wide range of software. And the new arm64 builds are laughably bad, having an almost 10-50% performance overhead on certain processes. And the Pi 4 is already painfully slow even compared to cheap android phones.
It is in most aspects an absolutely terrible way to get started with computers.
Originally Pi was created to promote CS learning and I get that it has some shortcomings there but it sure as hell has enabled a lot of people to learn about embedded computing and robotics.
I think the raspberry pi is mainly interesting for its small size, GPIO pins and very low idle power.