Just to be clear, I didn't upgrade to future proof, I did upgrade because I had enough of reloads with 8GB RAM. You may not have that issue with your usage of the iPad, but with the tabs I browse and the apps I use I do.You know what, this is Apple we're talking about.
The way I see it, they do things differently from the rest of electronic companies. That's why I don't see a huge benefit going from 8GB RAM to 12GB or 16GB with them.
They go at a different pace than others, they might or might not optimize their OS to work better with different amounts of RAM, they only upgrade the RAM and storage in base models every couple of years (always late), etc.
So, knowing how they are, I just don't trust that paying for more RAM will actually make things work better (Mac, iPad, iPhone, etc).
If anything, instead of trying to future proof with a 16GB RAM iPad I "embraced" planned obsolenced and took the cheapest option that didn't bother me as much now, which means I'll have to upgrade sooner. Will it get worse soon? Maybe, but I don't expect major changes in RAM usage with iPadOS 27 and 28 because the iPad 9 and 10 respectively need to be supported, but who knows. There is also the option to stay 1 or 2 OS behind. So I guess I am good for another 3-4 years, before 12GB start bothering me as 8 do now.
So yes, for me the "huge" benefit you mention is there, it's not as huge when you go to 16 (but I am still testing).
Having said that, RAM usage is only going up, at best it's staying the same, unless proper swap to disk is introduced, but at this point I don't believe that will ever happen on iPad (the current swap to disk is only for RAM intensive apps that want to use more than the standard amount of RAM apps are allowed to use, it's not a OS level thing), so 8GB are no longer an option for me on the larger iPad, and I'll be selling my M4 (my M1 and M2 are 16GB, but at some point I may be selling the M1 too).
 
 
		 
 
		 
 
		 
 
		