The Air now is a pretty compelling device IMHO: the M2 is still incredibly powerful (at least until they do something with iPadOS that requires more power, but that hasn't happened), you now have size options, the new Pencil Pro works with the Air (although the new keyboard does not) and it has the landscape camera. I kept my 2018 iPad Pro until now and upgraded to the 2024 iPad Pro... but had I gone with an Air instead I suppose I could afford to upgrade every 3 years for almost the same price as just getting the iPad Pro once for 6 years... I'm not sure OLED or M4 is worth it because by the time the OS really needs M4 you'll probably be buying the iPad Air in 3 years with M4/M5 anyway, plus other new features...
The Air does take a bit of the sting out of the price of the iPad Pro since they moved the Pro even farther upmarket. Last example... I "treated" myself to this iPad Pro to replace my 2018 iPad Pro... but my wife and two kids (college age) also have iPad Pros (20' A14Z, 21' M1, and 22' M2) and I justified those because it was "just" $200 more to get the Pro vs the Air. That's no longer the case with $400+ being the difference. With these latest changes the Air would be more than capable for the rest of my family and the price delta wouldn't remotely be worth it, nor would they care.