well why do you suppose the images are getting better?
I think that there are several factors.
Camera technology is improving in leaps and bounds. I've been using an ASI1600MC Pro, one shot color, camera for the last few months and I am absolutely astounded at how good it is. It's my second CMOS camera. My first was an ASI1600MM-cool. The 2600 just kills it in every performance category that you care to mention. I'm still using CCD for my mono work (a QSI 690) and have been happy with it. But I suspect that the mono version of the ASI2600 or ASI2600 would simply embarrass it.
The camera improvements affect just about every part of image capture and processing. Since noise has gotten so low, you can get great data with much shorter subs than older cameras. This relieves some demands on the mount. And processing clean data is just easier than processing data that needs lots of help.
Beyond the gear, I think that techniques are improving considerably. Part of this is due to the internet. It is so easy to share with other folks of like mind, that it's much easier than it used to be to learn how to up your game, especially at the high end, once you start getting pretty good at it. In the last 2 years, COVID has done a couple of things. First, it's given people more spare time. This (along with supplier and logistics issues) has made it harder to buy new gear), but it's made it so that people are probably spending more time on their hobbies than they did. The second effect is that pushing large masses of people to work remotely has introduced more people to online communities. This has improved both discoverability and the quality of online discussion and other real time interaction.
And finally, we should expect the quality of completed images to continually improve. Why would they not? If people find something that improves their result, they will do more of it. If they try something that makes the results worse, they will stop doing it (and may never even post an affected image, so you won't see it). The trend over time is only to get better.