Do you think there’s a threshold at which point non libertarians would agree taxation is theft? Perhaps when gov spending is 80% of gdp ? 90%. 100%? 110%?

We’re already now at 44% here in the US. And if you’re in the Bay Area or tech, almost certainly your paying a lot more if you count all the downstream taxes like property taxes permitting sales tax, and all taxes you pay when you buy stuff.