I just built a Ryzen 5800x / B550i / RTX 3080 (well, 3080 is arriving tomorrow) to replace an aging i7-2600k + 980ti build mid tower, used an 18L CoolerMaster NR200p case [1], and pretty happy with that case overall-- lots of flexibility, though a bit bigger than most of the SFF PCs.

The Teenage Engineering case looks great as a non-gaming, everyday-use build, if a larger GPU isn't needed.

[1]: https://www.coolermaster.com/catalog/cases/mini-itx/masterbo...