Though I would strongly suggest you just go ahead and go for FS2024 rather than FS2020. I understand and don't argue with the reason that some people here want to stay on 2020...
But if you're starting new anyway:
* The vast majority of FS2020 freeware and commercial add-ons work fine under FS2024 as of the latest update
* FS2024 runs more smoothly on most systems due to multithreading optimizations (I never fully eliminated stutters in 2020, never have them in 2024)
* You'll be able to access both older FS2020 stuff and the new 2024 stuff
* Better flight modeling on native 2024 planes
* More planes are included in the base sim
* Visuals are even better
* 2024 uses significantly less disk space by default, though you can download frequently used planes and scenery if you have Internet bandwidth restrictions
* A much longer run ahead of free enhancements down the road; these will start drying up for 2020
I'm guessing you were considering 2020 vs 2024 because you have an older system? But in my experience on everything from my high-end Core i9 to my anemic ROG Ally handheld, 2024 is more performant than 2020 due to its better optimization.
Obviously if you've made it this long on P3D, you're okay with not being cutting edge. But overall, there are very few reasons to start now on 2020 versus just starting with 2024.
(Again for those who've chosen to stay on 2020, I understand your reasons and I'm not criticizing the decision not to upgrade. Just sharing my opinion that expat will have a better experience if he goes directly to the new version. I think most of you understand what I'm coming for, but last time I mentioned 2024 advantages in the 2020 forum I got called mean names by at least one guy.
)