I just sold my 2020 12.9 iPad Pro and kept the Air 4. Neither one of those make any difference in real world usage. No one sits there crazily swiping back and forth between home screens looking for lag, which is the only real way to notice 120hz and you need to have them side by side to see it. very few are doing such intensive tasks on their iPads that the difference in RAM matters.
I’m a professional photographer and videographer and the Air 4 handled everything I threw at it just as easily as the Pro. I suppose if you were one of the very few that needed to run like 30 big apps at once, the RAM would matter. The Pro is a waste of money for 99% of buyers.
Sorry, but this majorly over simplifies the difference between a Pro and an Air. I don't even use an iPad in my workflow anymore, but even I think the Pro (if it had an A14/A14x) is worth the price premium over the Air. I find it ridiculous when people decide that because they look basically the same they must actually be basically the same device. They are absolutely not the same. The iPad Pro has:
ProMotion--it's a noticeable difference in refresh rate and I wish my iPhone and Macs had it
Brighter display
Slightly higher screen resolution
Quad speaker audio--it's a noticeable difference in volume and sound quality, especially bass
A 12.9" option--this is the sole reason a lot of people go with the Pro model
Higher storage options if needed
Nicer cameras
A processor that still beats the Air in multitasking
Whatever else gets added this month, because there WILL be an iPad Pro event.
Granted, the above list got a lot smaller than it used to be once the newest Air came out. And if I were to add an iPad back into my workflow today and needed an iPad RIGHT NOW, I'd be going with an Air 4 with Magic Keyboard. But once the Pro line is upgraded, which again, WILL happen this month or shortly after, I would go for a Pro.
It just still sounds to me like you are regretting your Air purchase because you're afraid the upcoming Pro upgrade is going to be too tempting. The newest iPad Air is a fantastic device. Use it and enjoy it until it doesn't work for you anymore, and then make an upgrade decision at that time.