We are all, in some sense, terminal. At what number of months or years left to live does your terminality become sufficient to let you try whatever?

It took about 40 years to find efficient ways to treat AIDS.

It took about one year to find efficient ways to treat COVID-19.

So, if you have a condition with a few years of life expectancy remaining, maybe it's worth it to wait for some promising scientific results to turn into an approved medicine that will cure you. If you have a few decades (e.g. the normal life expectancy), even more so. If you doctors give you a few months though, maybe the "try anything" approach is a better gamble.