With desktops and to a certain extent with laptops, you can upgrade storage, video, and platform components, pop in a Linux O/S and you've got a really useful machine. I haven't been able to do that with tablets. Basically you are stuck with a SOC that cannot be upgraded. Maybe if you get a high end tablet you'll have a more powerful system that'll last longer. But for what I do with tablets, it doesn't seem worth it.

My old Tab A 7.0 had a Snapdragon 410 Quad Core 1.2 GHz. The new one has an Octa Core MediaTek Helio G99 with the Cortex A76 speed cores 2.2 GHz. There's absolutely no comparison.

That hasn't been my experience. I think it is the chipset that causes the slowdown. My oldest Galaxy Tab A (10.1") from 2016 is the fastest even though it has 2GB RAM and the next fastest has 4GB RAM.  I'm basing this on how long it takes for updates to download and install. Exynos 7870 chipset. (Octa-core) (I prefer to select and install the updates I want on all my android devices rather than having them auto download).   The Galaxy A8 (10+")from Dec 2023 is the next in speed. Qualcomm Snapdragon 425 (Quad-core)   The turtle of the bunch is the 2019 Galaxy A8 (8"). Unisoc Tiger Cortez A75 and A55 (Quad-core).  Model SM-T380 not SM-T290 which has a Qualcomm Snapdragon chipset.   When I'm ready to buy another tablet, I will pay closer attention to the chipset.    

It all sounds good until you realize the companies aren't interested in making something that can be repaired or sold second hand. They would rather you buy new every couple of years, appliances included. Society as a whole would need to change to the point where people would rather buy something that's repairable than the latest and greatest.