"The AI being incompetent" explains a lot of victories in this game. Spies and war are generally the only answer if you spot an opponent nearing victory before you can hit your chosen VC because other options are generally game long commitments. The likelihood that you can sufficiently ramp up domestic tourism in the last few turns like you've described is low. At best you may slow them down a couple turns at the risk of slowing your own VC. I'm saying this because the game appears to be designed so foreign tourism inevitably overwhelms domestic because of all the late game tourism modifiers. If the answer to how to generate more DTs is to ramp up population, increase culture generation or some other peaceful non sabatoge way would you change much about how you're building or would you just race to your own victory? Especially considering the quicker easier solutions you have at your fingertips? What I keep asking is even if this information were crystal clear in your hands would it really impact the meta?