I understand the point you are trying to make, but Android has not existed for 20 years. Anything before the G1 is irrelevant. That said, you also have to discard anything you used that wasn't Snapdragon, since Qualcomm and Mali (or others) are simply not the same thing.
Now that you are looking at a much less impressive list of past devices, you have to consider that you aren't actually overclocking and the 888 is currently capped. You also have to consider that the 888 does perform much more efficiently, so it may even seem cooler than an S10+ when doing the same basic tasks. After all, the 855 was known for getting hot and is now two generations back in terms of performance. When you notice the heat is when you run things the S10+ would struggle to handle.
The problem I was actually pointing out was comparing the 865+ and 888. The 865+ clocks higher than the 888, but the 888 runs significantly hotter. Running the same games on an 865+ and an 888 will yield higher temperature from the 888, but only marginal performance improvement. The question is what happens when you try to run the 888 at its full capabilities?