Some full size desktop computers run more quietly than mini PC with a faster Intel or AMD CPU because Some desktop computer have a large CPU heatsink cooler with a large slow spinning cooling fan which generate less noise than mini PC fans which use smaller fans which spin at a faster speed to move enough air to cooldown a CPU.
I think a full size desktop with a large metal CPU heatsink and big slow spinning fan would be a better choice if you prefer a quiter PC which can properly cool a PC without needing a fast spinning fan to cool the PC's CPU.
I think a full size desktop with a large metal CPU heatsink and big slow spinning fan would be a better choice if you prefer a quiter PC which can properly cool a PC without needing a fast spinning fan to cool the PC's CPU.