What I meant by saying "physical navigation and manipulation of physical environments is the hardest problem to solve for" is that it won't be in the first big round of automation which is what we're now slowly starting to see happening, thus investing in those areas is premature. Kinda like investing in "palm-top" smartphones before the internet had sufficient penetration. You should invest in that area after this initial automation of digital/intellectual workers to achieve the highest financial return. Programmers, Lawyers and Pharmaceutical researchers will be replaced long before self driving is solved.

I also disagree that there is a large barrier to entry to a strong AI. There is a large initial investment to it, but after the initial investment has been done in terms of R&D, algorithms needed and hardware configuration it works on it's trivial to build. Look at current Transformer model and how newcomers quickly are able to make State of the art (SOTA) products like Stable Diffusion. This showcases that the AI makers won't be the winners here, they are like the enablers. It's not like the steam engine builders were the big winners from the industrial revolution, it was the steam engine users that generated the most value, I expect the same to happen with AI because the barriers to entry are indeed, not that high.

You make a great point towards existing businesses having "sticky" practices with margins priced in which is ripe for disruption. But in that case the businesses best to invest into don't exist yet as they will be startups, which wasn't the question at hand, the question was which companies should you invest in now.

Due to my assumptions listed above I think the worst financial mistake to make is to invest in companies that are actually building the AI systems as they are investing R&D into something that once completed has extremely low barrier to entry and it would render their own core business obsolete. Which is why I think it's unwise to invest in something like Alphabet.

I also think it's counter-productive to invest into companies that has a too long-term vision and won't benefit from the short term automation of intellectual and digital workers like Tesla. They invest in what is probably the 2nd or 3rd wave of automation after intellectual workers are already gone; Navigational and physical manipulation. I would hold off on investing in Tesla and use your capital to benefit from current capabilities which are large transformer model AI that can disrupt intellectual workers. The return horizon on self-driving cars and robot workers is just too long to be worth the investment in 2022.