If backwards compatibility and biggest library of old games that still run as well as multi-platform games is ALL you care about, then you might as well just get a PC!! With MAME and every other known emulator you can play PC games from 40 years ago, as well as Consoles games too, all on your PC. You don't need an Xbox One for that.
If you already own the games on Xbox, it doesn't make sense to ignore that library and purchase them again on PC.
That is the big advantage on offer here from Xbox.
My post was specifically directed at the original assertion that...
"Xbox One is the best console if you don't care about exclusive new games"
My other point is BC, whether done via Sony's crappy offering or all the development time Microsoft has invested, doesn't have any long term value, IMO. Gamers buy new consoles to play new games, whether that is a totally new IP or Version X+1 of the game that was on the last gen console, or a remastered version of a classic. No one wants to play ALL the crappy games from the last 7 generations, even if you did own them. There are only a few games each gen that push the boundaries of story, gameplay, graphics and might just be fun, that are worth bringing back as a remaster or re-imagining in future gens of a console. The vast majority are just poly-filla/bumph.
That is the reality of each generation.
So rather than spend that time/money on BC, Microsoft could have been investing that time/money in new gaming experiences that really take advantage of the Xbox One X's power. So many missed opportunities. SMH. Maybe they will pull a rabbit out of the bag at E3 and blow everyone away. But even if they do announce new IPs etc, those will take another year or so to hit the shelves. God of War was 5 years in development to get it to the state it is at today, with all the plaudits it has achieved. Microsoft need a AAA game that literally causes mouths to drop visually, a great story and amazing game mechanics. Gamers are getting used to quality across the board of a game, so Microsoft better step it up and grow up with their vision of games and what gamers expect.