From what I've heard from a few YTers that I follow, the game is basically pretty good, and an overall improvement on the original, but with two caveats. First is that they shat the bed when it came to login servers and by far the most of the negative review bombs are from people who could not log into the game after launch. As one pointed out, this is nothing new, devs have had this problem for 20 years, but you'd have thought that by now they would have anticipated it or solved the problem - especially Microsoft. The second is that you need a seriously beefy internet connection to download and render the world graphics a lot of the time.
Overall, it seems to me if you're a flying sim guy, wait a month then buy it. If you are only meh and still own 2020, keep that.
Here are three shortish vids discussing the issues and generally talking about the game: