There already is an upcharge version. It's the club level only option and you can book your FP 90 days out:
https://www.disneytouristblog.com/paid-fastpass-club-level-disney-world-thoughts-info/
The real cost of that is getting the club level room. Checking on club vs. regular for when I'll "be there" in Nov. No luck. I think WL has the cheapest club-level rooms with access to this and their lowest rack-rate is $611 vs. $366. So $245/night to get access to buying 3 FP for $50/guest/day. So my family of 4 is $445/night extra, or over $800 total.
We've used the Express Pass at Universal when we stayed at the Hard Rock and it was awesome. That was around $450/night for the room. You can buy the express pass for like $90/person/day, so the benefit of the hotels with that seemed quite worth it to me. I think WDW has too many rooms at deluxe hotels to offer this perk.
WDW will always have a version of FP that is free. Imagine a 4 day trip w/o them. You don't get there early, and all you get is the full standby lines. My memories of trips pre-FP have lots of waiting in lines. Even if you choose to wait for things, you still have those 3 lines each day you skipped.