I've had many ideas that have been watered down by the editing process that by the time I'm done have lost the impact or connection to the original idea.

Maybe I lack the vocabulary? Writing skills? Maybe I'm self censoring? Maybe it's my perfectionism optimising the local maxima?

I don't know but I do know writing has ruined some, not all, of my ideas.

This also wasn't my main issue above. I was more concerned that the idea you can't have good ideas without writing them down was deeply flawed and a bit gatekeepery.