Is MuseScore 4 still . . . not good?

It seems to me that people need to use the software that works for them. That goes for any software. I use notation software for composition only. And for playback. I doubt that anyone would want to play anything I write.
I have Sibelius 7.5.1. The UI and how it interacts with a score, and the number of ways it manipulates a score, are far superior to MuseScore. There are far more sounds and variations. The sounds are good, but a little dull. It’s an old program, and someday it won’t work on a future version of Windows. So, I started using Musescore. 2.5. All the way to 3.6.2. Since I’ve been on the Forum, I read about people using MU3 in ways that I never would have dreamed of. And they’ve based their workflow around these things and do many things very quickly. Many of these things have, in my opinion, nothing to do with the purpose of notation software. That doesn’t make them wrong, by any means.
I started re-working Sibelius files into MU3 files. There always seemed to be something missing. No matter what fonts I used, playback was always a little dull. That’s fine, I guess. Or maybe not.
When MU4 beta came out, I downloaded it and Muse sounds. I loaded a score originally from Sibelius and had been modified in MU3. I hit play. As a result, I deleted MU3. I have no use for it. Period.
There is a plethora of features that MU3 has that MU4 does not. Most I did not use, or don’t miss. The first main complaint seems to be that things are missing. As a result, MU4 is a regression. Released too soon. A mistake full of bugs. The second main complaint is that MU4 won’t run on their computer. After all, MU3 ran perfectly. Having used Sibelius, I knew where to look to start making the proper adjustments. It works fine on all my computers.
Is MU4 perfect? Of course not. No software is. MU3 isn’t perfect, either. Nor is Sibelius. They are three different programs. There are things that each can do that the others can’t. If MU3 works for you, then there may not be much reason to even try MU4. It just depends.
But then, my needs are simple. I want good playback. Is MU4 perfect? No. But a darn site better than MU3.

I haven't had issues with corruption or file loss with MuseScore 4. The only bugs I've experienced recently are a few minor playback issues (such as glissandos not playing on tied notes) and, at worst, a couple of VST plugins that instantly crash it.

The most annoying thing to me is the fact that dynamic markings don't do anything to the notes' velocity when using soundfonts or VSTs (all they do is change the volume). Updating old scores to MS4 basically requires you to change all the dynamics, whether you're using Muse Sounds or not, if you want it to sound right.

I agree that it was... kind of terrible when initially released. 4.0.0 was a mess. But now, while it's not perfect, it's completely usable. I still use MS3 if there's ever a score that wouldn't benefit from MS4's features (accel/rit, multi-measure repeats, several other things, and of course Muse Sounds and VSTs).