You can buy server boards that don’t require loud fans. If you’re buying used server gear from a datacenter then it will be like what you said.
I have a 4U NAS with a supermicro board and an i3 chip with 6 WD Red NAS drives and it’s very quiet. The chassis came without fans so I installed the brand I like.
no, you definitely cannot. you probably have a consumer board in a 4u case
Completely wrong.
Tell my youve never owned a supermicro board without telling me. They support regular 80mm/90mm Noctua and function just fine. There's specific supermicro mounts for me.