I didn't say wins and losses are the be all end all, but it's a big part of it.
The whole point is that yes there is levels, but if your booking is what is preventing someone from reaching the next level then that's a problem. You said yourself Riddle is over and sells a ton of merch. So why isn't the booking matching that? When Austin got hot and started selling shirts they didn't have him go out and get squashed by Justin Hawk Bradshaw. And again, I'm not saying Riddle should never lose. But literally THREE DAYS after he has a huge TV rating with Reigns, you immediately send him out to get squashed and kill any momentum he had? There's a time and a place for losses, but that is tone deaf booking. You have a chance to have a dude separate from the pack and completely miss it.
And so Cokeboy sits around going well fukk nobody is over enough to face Reigns, let's call up Brock. But the reason they have to keep going back to Brock to sell tickets is all self inflicted bc they don't book anyone to stand out at that level.
The only regular roster guy who has any shot right now is CAWdy bc he was lucky enough to get injured before they could eventually have him in a 50/50 feud w/ someone like Sheamus.
Literally the best way to boost your stock in WWE is to be booked like teflon like Reigns, or be off TV frequently enough that they can't book you to always lose.