The main number goes up when there's a stable release. A stable release is one without any bugs that weren't also in the previous stable release. For most people, this doesn't mean it's better as it's possible to fix hundreds of serious bugs, but add a few minor ones, and, despite being much less buggy, still not count as stable. This is the case with Dolphin (although it's thousands of fixed bugs rather than hundreds). Sometimes fixing the few regressions isn't worth doing just to make the main number go up by one. For example, it can require a feature freeze where no one adds anything new while the regressions are all being fixed and testers test that there are no unknown regressions, and that means things that might be much more impactful on users don't get done.
OS: Windows 10 64 bit Professional
CPU: AMD Ryzen 5900X
RAM: 16GB
GPU: Radeon Vega 56
CPU: AMD Ryzen 5900X
RAM: 16GB
GPU: Radeon Vega 56
