I treat my vehicles to an extent where they become some of the quietest examples of that vehicle. It isn't cheap if you're buying quality products. I've done 100% coverage of deadener, foams, and MLV on several vehicles over the past 25 years. The idea of a product that combines these isn't new or novel, but it's hella expensive when done correctly and terrible on any surface that isn't flat. The main issue is the inability to properly roll the deadener into place, for proper adhesion and bonding. This is why you don't see this kind of combo. You will find MLV and foam bonded together, or foam and lead sheets which bend easier.
Noise comes from the doors, the floor (wheel wells, trans tunnel, rear seat, floor, etc), the roof, the door seals, the glass, etc. Treating a whole car takes about 140 hours and you spend a grand for the cheap stuff. Don't forget to treat all of the interior panels before you cover up the metal surfaces that you've treated. Everything behaves as a system and each layer plays a role.
The reality is that anyone can have deadener made, anyone can have foam made, and they get to choose the price point based on quality and specs. Will that product stick properly on vertical surfaces and provide useful elastomeric properties? I would guess not given the price. Will it stay on a floor and improve transmission loss? It would be better than nothing at all, for sure! There will challenges on irregular surfaces since it does need to be 100% on the floor, wheel wells, and rear quarter panels. Bending it will be tough, but not impossible, and your seams need to be sealed. It's tedious, and after that effort you'll have treated one of the eight sources for noise. Hell, on a really budget build I laid carpet padding down and covered it with thick vinyl flooring in a pickup truck to treat the floor and rear wall. After getting the factory carpet back on, the truck was noticeably quieter - in that the floor was no longer the loudest source. When you treat one area, the next loudest area becomes apparent. And you'll only hear one source at a time (usually).
Certainly, many (if not most) people just slap the cheapest stuff they can find, and they do 100% coverage, and it's better than it was, and they are happy. It's your car, and you can work in phases or stages as funds become available. You'll learn along the way!