It was pretty well understood by the 1960s that smoking was harmful. The big tobacco settlement was in 1998. That is an extremely bad example of tort being a sufficient alternative to regulation.

If we're on a similar timeline with AI if we reach a consensus that AI is dangerous today, then we'd be looking at a big lawsuit finishing up around the year 2070, give or take a few years. I'm not sure if we need regulation, and I'm definitely not sure that regulation could actually be effective for this, but tort a la the big tobacco lawsuits is definitely not a reasonable alternative.