There's two issues, success rate (about 5%) and time ... even if it is successful in humans, it will be 5 to 10 years before it's available (and 20-30 before it's affordable)
He was a super-rich guy, who had had too many people telling him he was a genius for way too long (reminds you of anybody?), and so was way too sure of himself. A bunch of his ideas were crazy, which doesn't mean others weren't trying to dismiss his views.
The benefits may be statistically lower, since you may have been infected by some of the variants already, older males may have fewer sexual partners in the future, and cancer takes a while to develop.
In the USA, it is recommended by default for adults up to 26 and kinda for 27-45.
This is not being a contrarian, but a realist.