I did the same research and your second set of points are spot-on. Hybrid mattress with pocket springs are amazing.
The only physical store worth a damn is Ikea. Their hybrid mattresses aren’t bad and decently priced. Although it tended to sag after a few years, it was still worth it for the price I paid.
I’ve since gone with Titan mattress and have been extremely happy paying a bit more for the increased quality and durability. I’ve had mine for 3 years and it hasn’t shown any signs of wear.
Their hybrid mattress is damn good for the price, especially when it’s on sale. Not everyone can afford spending so much money. At the time I couldn’t, that Ikea mattress was leagues ahead of the competition.