I had a 2018 64GB 11” iPad Pro that I just replaced yesterday with a 256GB M1 11”. I did not really need to make the upgrade, but my wife wanted an iPad and this let me get one with more storage (the 64 was just a little too tight). Other than storage, there is no noticeable difference. The iPad Pro has been ridiculously overpowered since the 2018 models in my opinion. The only thing that would be a notable upgrade could be the mini-LED screen. Even then, it has plenty of people who claim the difference between the 2020 12.9” screen and the 2021 12.9” is not life changing. And it came with a price increase to boot.
Both the iPhone and iPad are mature devices that are not likely to ever really see a massive leap again. They will make small incremental changes that, over the span of several years, will add up to a nice upgrade when the old machine is ready to be handed down or retired.
As for those talking about RAM and reloads. It is my understanding that while Apple did increase the amount of RAM on the M1 iPads, it did not increase a single app’s RAM limit.