Of course it's debatable. The winning team has much less room to deep ward the enemy jungle. By default the red/blue buff areas are just fully fog and offensive wards do nothing until they're placed far deeper into the jungle, making that experience more difficult and riskier.
It's truly disingenuous to only take the negatives of one side of the argument. Oh the losing team can't play this one control ward play. OK yeah, I agree. The winning team also can't deep ward that entire area. The losing team arguably has better access to warding the river (seeing enemy champions go in) than the winning team has access to the opposite side of the chemfog. Every invade is immediately risky until you can get wards down even deeper. And even then, did they cover every single entrance? No. OK, then good luck invading red buff. You literally can't know if Leona and Olaf are waiting for you. I don't believe you can just dismiss this out of hand. You can believe one factor is stronger than another, and that's great. Let's have a discussion. But absolutely no one can definitively claim they're irrefutably right.
And I think it's disingenuous to say the champs/runes examples are irrelevant. I'm making the point that even expert players make mistakes. They don't see the full picture. They experience the game and try their hardest and still believe incorrect things. Something as simple as a Keystone choice is a great example of that. Doinb went Q max on Malzahar at Worlds. Just because people are very good at the game doesn't mean they know everything. So you just cannot say, "Oh yeah, we're two weeks in, we definitely know how macro is going to shake out."
I agree seeing snowball win rates or game time changes in Chemtech Rift would be a reasonable approximation. You still have to do all the caveats for direction based on MMR and accounting for players learning (e.g. champion win rate changes as players get experienced, so winning/losing team power could do the same here), but it's be a lot better than, "Well you can't do this one exact control ward play."