I played with it on an OrangeCrab [2], and was shocked by how easy it was to get it running and by how well it worked despite the slow clock. The FPGA design includes peripherals for GPIO, PWM, serial interfaces, etc., and the kernel includes drivers to talk to them. On the OrangeCrab, everything I thought to try pretty much just worked as expected.
That being said, this is mostly just a fun exercise in SoC building, and isn't going to give you PC-like performance. VexRiscv is small and fast and super configurable, but you're still looking at "high-end microcontroller" rather than "low-end application processor" levels of performance.
The mother lode of cheap, capable FPGAs seems to be supply chains for makers of TVs.
I bet most don't plan to let customers upgrade that way, instead of buying a new TV. I expect they will sell the same hardware with a different model number and just new firmware. They like changing model numbers frequently anyway to frustrate reviewers and people consulting them.
I once stumbled upon an article where somebody FPGA-ed (with a much bigger board, I don't insist it has to be this small and simple) a RISC-V system to make a "RISC-V PC" and I'm thinking about getting an FPGA to explore that since then.