I mean, winning that bet would be kind of a Pyrrhic victory.

I'll refer you to 2008. I suspect my future self will also refer you to 2023, but we shall see!

Nah. Not enough oxygen in the atmosphere to support terrestrial arthropods much larger than the ones that currently live on Earth, or Jorō spiders would be much less remarkable for their size - there's only so much you can do with the relatively simple means of oxygenation that arthropods have thus far evolved.

A shame, if you ask me. Social wasps are already quite smart despite having only a few hundred thousand neurons apiece to work with; I think I'd quite like to live in a world where the largest hornets were perhaps dog-sized, with brains to match, or indeed much larger still. If nothing else, maybe people wouldn't so often look at me funny for how well I get on with wasps and spiders, as if there were some absurd betrayal of essential humanity in the simple act of not being frightened by animals compared to even the largest of which we may as well be so many walking mountains.