game two, Bob floated all that mana, then cast upheaval, then could flood the board with permanents, and win easily with a processer, or a masticore, or something else, and Gabe couldn't rebuild his board nearly as quickly so there's no way he could win. That's why he scooped it up.
Old school player here (I stopped a bit after masks block)... I just found out they did away with mana burn... Jesus fuck! Think about how much MORE broken tinker would be, than it already is, if fucking mana burn wasn't Ann issue... 🤦