> Another perspective is, you shouldn't be doing this if you can't tell if something is fun without "testing" it.

Trust me, you have absolutely no way of knowing until you playtest, seriously. You could copy all the game mechanics of a popular game, down to the engine and the exact magic numbers and functions that made it, and it can still suck. Just look at most AAA open-world action RPGs released in the last 5 years.

> Without fail, all the people I know who are the best at this keep having one good idea after another. They absolutely do not run out of really good ideas that sound and play obviously fun.

I'm sure the people you know do have "really good ideas" but they are nothing more than lottery tickets until prototyped. You don't need money to pull together a shitty prototype to prove some aspect of your game works, and there are numerous meetups everywhere for indie devs to show off their games. I'm gonna make a wild assumption that these people you know haven't prototyped any of these "obviously fun" ideas.

> Trust me, you have absolutely no way of knowing until you playtest, seriously. [Conflates a bunch of things under the word "suck."]

Being a product manager employee and a Lead Game Designer employee are both very valid and interesting roles.

Your name couldn't fit your argument better. It is naive to think one can develop fun games without constantly playtesting them during development.

It’s both, you need to have developed good taste and you should take an iterative approach to development.