It depends. For the kind of thing you can do on an iPad just with the tablet and no magic keyboard or other mouse/kb plugged in, it will make virtually no difference.
But it is worth noting that the standard is changing. iPad Airs and iPad Pros going forward will at least have the M1 chip, which is a desktop class SoC, and a version of iPadOS (16) that lets apps use virtual memory for the very first time, as well as allowing floating windows and external display support of up to 8 apps running side by side.
The M1 isn't just an A14 with more cores - having a chip that has Mac-class storage and Mac-class RAM and an OS that does virtual memory is a landmark, and as we go forward, the apps will get more and more complicated and memory hungry, and those on the A-series chips won't be able to run them side by side or as well.
As I said, when you're just holding the iPad and using it, there will be almost no difference. But if you're planning to keep the device for 3-4 years, being stuck on an A-series chip in 2025 might not be worth the small money saving back in 2022.
As the iPad becomes more like the Mac with each passing year, ask yourself this: when is the last time Apple sold a Mac with only 4GB of RAM?