Realistically, we would need to raise like 10 million so we could work full time on it and buy quality art. Outside of that it's just a pipe dream.

If someone who actually knows how to run a business, wants to start this up I would gladly work at half of my corporate rate.

If I was a billionaire I literally would do nothing but fund to open source video game projects. And then maybe pull a Red Hat and monetize it somehow.

A high-performance, multiplayer MVP would be the first order of business. No need for art so early. Remember fy_iceworld - that did not need much art!

The question is, what to build it on. Godot?

Depends...

Are we talking about actually getting this done or just dreaming of a nice billionaire giving us money ?

https://codeberg.org/Liblast/liblast-framework

I'd start with that if you want to build it in Godot.

However, I'd prefer to build it from scratch with an actual engine designed for an FPS.

ID Tech for example makes amazing FPS games that aren't resource hungry.

From 30 seconds of googling,

https://github.com/RobertBeckebans/RBDOOM-3-BFG

Seems to be a modernized version of the last Doom engine.

Hypothetically if we could actually get a team together I'd put up my own money to get art done. However, I still think creating a high quality FPS would require money at some point.