To put some figures to it, Debian's popcon [0] lists it as having 100k installs (out of 200k 'surveyed' systems). For comparison Steam has 6k installs in the same survey.

Steam claim to have 67M active monthly [1], and 0.6% linux users; ~40k linux users.

Guesstimation: if the 200k surveyed on Debian are representative and Steam installs is a representative sample then we can estimate that if the 6k installs of Steam represent half of the Steam surveyed Linux users that [3] ~300k people are using GIMP on Linux.

In the popcon survey a fifth of users are regular users.

On other OS users have a wider range of good alternatives IMO, but if we recall that Linux desktop usage is about 1-4% then we can expect of the order of millions of other GIMP users.

The number suggest one could call it successful.

[0] https://qa.debian.org/popcon.php?package=gimp, https://qa.debian.org/popcon.php?package=steam [1] https://www.geekwire.com/2017/valve-reveals-steams-monthly-a... [2] http://store.steampowered.com/hwsurvey [3] 40k users of Steam, if half are on Debian-like systems and a 200k sample of them show 6k steam users that's 3.3 times less; if GIMP then is underreported to the same amount we can provide a rough minimum actual installs on Linux.

>It's been 20 years now without any success. Maybe it's time to move on?

A huge number of users is not what I'd call "without any success".

As I mentioned elsewhere, when I got serious into photoediting about 10 years ago, GIMP was the best alternative to Photoshop - better than any other commercial tool.

I use it all the time for makingjournal figures. Simple stuff. Cropping, rescaling, color based selection, recoloring, gradients, etc.