Fujitsu Q556, Lenovo ThinkCentre M700/M710q/M715q/M910q/..., or something else that does use a >=6000 gen Intel or a comparable AMD chip. >=4000 gen if you get it very cheap. If you compute requirements are low you can even go with a Atom for <40€/$.
There are often offers that sell these machines for <100€/$ all inclusive, sometimes <80€/$ (at least here in Germany). You get:
- much more CPU power (with the 6100t 3 to 5 times more for example. https://www.cpu-monkey.com/de/compare_cpu-raspberry_pi_4_b_b...)
- more GPU power (transcoding for streaming possible)
- no Micro-SD write issues -> proper SSD, easy to add another one
- in most cases 8GB RAM or more (also very cheap to extend)
- no issues with ARM docker images (sad but sometimes still the case)
If you need lower power consumption, HDMI-CEC, GPIO pins or a low form factor, the Raspberry is still 100% the solution you are looking for. Otherwise you might be happier with the options above.
I currently use an old Asus T100TA X86 tablet with Ubuntu patched onto it because I still had it laying around. Works great and does use very little power.