There was a small resurgence of some boat restorers re-gelling the whole boat.
It ultimately is more work but materials cost less than some paint jobs...so really a push.
The paints of the last few years are tough to beat....and not many places I have heard of will re-gel a whole boat.
Assuming we're talking about the entire boat vs spot repair.
I'm having my 1970 Willard 36 repainted in Ensenada MX. Yard offered to gelcoat instead of paint and had a very nice recent example of a 40-foot sailboat to show off. Same overall cost.
I posted to this forum - I also pinged Steve D'Antonio who, in part, provided the following describing that two part paint is strongly preferred to re-gelcoat:
. In short, other than for repairs, gelcoat is best suited for use in a mold, i.e. it is applied to the inside of a female mold first, then fiberglass fabric and resin are applied on top of it, before the gelcoat is fully cured, thereby creating a very tenacious, chemical bond between the two.
Applying gelcoat, in paint-like fashion, for deck, cabin or whole hull applications, after the fact, has two results. One, it does not achieve a chemical bond with the underlying substrate. Two, when gelcoat cures while exposed to air, it becomes porous. Furthermore, gelcoat tends to be somewhat brittle, much more brittle than paint, so if it is applied too heavily, especially over an area that might flex, adjacent to a hinge or cleat for instance, it tends to crack. Controlling gelcoat thickness can be challenging, especially when used in this manner. None of these features are desirable.