First off, you can pick up a used SC for a much better price than new. We choose screens not for price but ability to be able to see it in bright sunlight. Any cheap tablet or phone looks great in a darkened room but we don't fly from such places.
Then there is the amount of extra stuff to carry and plug in each time you want to go flying. If you choose a tablet that won't fit in the control holder arms then you also have to buy and fit the adapter to hold your tablet plus fit the tablet into that adapter.
So take all that into account when comparing a SC with a tablet. No tablet can stand up to the screen brightness and ease of use and no cable connection and no adapter to fit and hold it, when compared to a SC. Therefore, it is a No Contest sort of comparison and rather pointless.
You can buy a new iPad mini for less than the sc used with 50% more screen and quite comparative in brightness in REAL WORLD use ( and easily use it for other stuff). My iPad mini fit in my regular controller (Mavic 1 or 2) with no adapter. I had the SC on Mavic 2 Zoom and PERSONALLY prefer the larger size screen of the iPad mini. Yes, a bit less convenient. Yes, 1 extra cable. Yes, a cheap tablet is not good but compare a good tablet for fair comparison. Biggest gripe on the SC is that the screen is smaller than my iPhone 12 Pro Max if I wanted to use that. Have you tried an IPAD vs SC for brightness? I’d never use a full size iPad (weight) but it sure makes it easier to see. The SC is no lightweight either. Definitely convenient though.