Yes, you can get a random PC that is faster than a Raspi for cheaper. But it is a random used PC which you have to individually set up. Not counting that it is much larger, usually not portable and needs more electricity.

The Raspberry Pi 400 is a pretty much usable desktop computer out of the box which you can buy as a complete set for 100€ new, including a nice book. It is also very nice to use as it is compact, very portable and doesn't need more than an USB power supply.

In comparison it is very easy to grab an used screen, as the screen doesn't need to be set up. In addition, the Pi works well with a current TV. Brings back the best of the home computer age in the 80ies.