Designing the ideal server for forge minecraft

For the last 5 years, I’ve been looking to find out what would be an excellent server for Minecraft. This seems to be a decent build (with ram of course) what are y’all running and how many players/mods can you do? Also, how do the massive servers with thousands of players work?

Rack servers like this are good but they also have many downsides the biggest being noise they are very noisy so much so that they are not ideal for this reason alone unless you are serious and have a dedicated room for it or rack that has noise control.

They also are very warm and put out a lot of heat enough to actually warm the room they are in considerably. They also consume quite a bit power.

I have a few decommissioned rack mount servers that i have no interest in using because the downsides outweigh the benefits.

This day and age consumer computers are offering everything we need i opted to go for a sff build currently because sff boards have less components and really only have the bare essentials that we need for a server unless you are trying to buy a top end gaming sff board which you don’t need all it needs is a cpu with good oc capabilities. They are way more quiet more power efficient and less power intensive.