Not GP, but I believe Polyphia [1] self-produces on a laptop in a bedroom (or at least did when they started out?).

1: https://www.youtube.com/watch?v=9_gkpYORQLU

I make 90'S-ish indie rock. I play all the instruments (drums, guitar, bass, keys) and sing.

Having to self-promote is the main struggle, and that's the only way to "make it" anymore. Similar with the book publishing industry. My wife spent a year writing an amazing book, paying an editor, but when shopping it around to publishers, none of them would bite because she didn't already have a social media following. They expect you to have 20k followers knowing that X percent of those will buy the product.

And any time spent self-promoting (especially before launch) is time not spent on the key creation itself. I imagine having a natural interest in it and/or then a very low-touch habit of creating and promoting is important. e.g., set up a camera as part of the writing or recording process, and find a highly-imperfect option for editing the resulting media for upload.