Biology especially human biology is a lot harder simply because experiments have bigger ethical issues.
Even if you have desperate cancer patients there are limits how and what you can test.
And we have others fields where all these brilliant people according to him are working and all the money goes and the problems are also not solved.
A human body belonging to a lucky person might live the better part of a century, all the time which it grows, heals itself when injured, processes food into new resources, hosts an example of the best known thinking machine in the world (the human brain), and literally has the machinery to produce one or more additional human beings. These are capabilities which are incredibly difficult to replicate artificially, so much so that producing a robot that could do even half of these things remains firmly in the realm of science fiction. And it wasn't designed, it was evolved, so it's about the worst mess of spaghetti code you could imagine. It's simply a hard problem.
In physics you can totally shatter your test object to get to the inner functions.
You can't do that with living creatures especially humans.