Juust putting this out there:

1. Some people made good money from shareware in the early home computer days.

One example:

https://en.m.wikipedia.org/wiki/Jim_Knopf

https://en.m.wikipedia.org/wiki/PC-File

Knopf originally wrote the software for his own use to manage a church mailing list, on an Apple II. Later, he ported it to CP/M, and then to MS-DOS. Other people heard about it, and started requesting copies. Eventually, the cost of sending out update disks inspired Knopf to include a note requesting a small cash donation to offset the expenses. The response was overwhelming, and when his income from PC-File exceeded "ten times" what he was making from his job at IBM, he decided to turn Buttonware into a full-time business.

2. Current stuff too, like Mike Perham's https://en.m.wikipedia.org/wiki/Sidekiq

https://news.ycombinator.com/item?id=35566768

mperham: ... I'm closer to $10m than $1m in annual revenue now.

Mike Perham, Creator of Sidekiq: From Employment to Independence:

https://codecodeship.com/blog/2023-04-14-mike-perham

There must be others ...