IMO Apple is killing it with the mac mini too. Obviously not if you're gaming (that has a lot to do with the OS though), but if you're OK with the OS, it's a powerhouse for the size, noise, and energy required.
You can hear the fan at full load, especially on the M4 Pro. I really wish Apple went with a larger case and fan for that chip, which would allow quieter cooling.
Also, many units are affected by idle (power supply) buzzing: https://discussions.apple.com/thread/255853533?sortBy=rank
The Mac Mini is quieter than a typical PC, but it's not literally silent like, say, a smartphone.
My Mac Mini M2 never does any noise, even when I run FFMpeg the fans don’t spike. It just gets slightly warmer. Still, unless I’m doing these high CPU bound activities, every time I touch it it’s cold as if it was turned off, which is very different than my previous Intel one that was always either warm or super hot.