After 20 years of using clipless on the road and for mtb, I largely stopped using them on the road about 3 years ago. I was 48 at the time, not sure if that counts as "late in life".

Honestly, I see basically zero benefit outside of intense bursting sprints to run clip-less on my road bike over GOOD flats and shoes. If I were racing or riding with people trying to drop me on bursting sprints I would run them. Otherwise, I find pretty much every argument I see for them fall into 3 categories:

1- Unsubstantiated conventional wisdom
2- Real life comparisons of clipless to flat pedals, but based on experience with sneakers and cheap flats, rather than quality flats with pins and cycling shoes designed to be used with flat pedals (and there is a BIG difference)
3- It is what pro racers use, so it must be better.

That said, definitely try clipless if you are interested. The only real DOWN side I find is that I have to swap pedals on my bike sometimes. They feel different than running flats, and it is really just personal preference.