If a 200mAh 3.7V battery (0.74Wh) takes 1.5hrs to charge over USB-C, is there any benefit to charging to one the of available higher standards above 3A (USB-C v1.2) i.e. USB PD v3.0 will charge at 20V/100W/5A.

Many thanks.

At 200 mAh, this is too small for a cell phone battery, and that is the only familiarity I have with USB-C fast charging.
I'm fairly certain that, for cell phones at least, the charging rate is determined by the phone's electronic battery controller, and simply switching to a higher rated charger won't make any difference.
( I think my Samsung gets 50 % chrge in half hour )

It was actually for a rechargeable battery in a torch:

https://cyanskylight.com/product/m1r-multifunctional-keychain-light/