> or worse placebo

Just to be clear, most drug trials for anything where we have an effective treatment are not “new drug vs placebo”, but instead “new drug vs standard of care”. Thus the goal being to prove it’s better than what already exists.

Sure - it rather depends on how good the 'standard of care' is or how much consensus there is on what that should actually be.

If the standard of care is already good and you don't need a placebo - then you have another problem - you probably are going to have to do quite a big trial to get the stats to show a significant difference, and you are going to find it harder to persuade people to participate with an experimental treatment if there already is a fairly good treatment.

The whole point about the challenges with clinical trials is that it's not an intellectual exercise in designing the perfect experiment and 'just doing it'.

It's about persuading yourself, the regulators, the doctors and ultimately the patients that it's something you should try - and before you've done your first trial you don't have any human data to show it's safe and effective - all a bit chicken and egg - the solution is often to move slowly in stages.