Yes, using the best filament for the application should be the first step. In most cases that’s enough. And yes, doing a composite layup would be a lot of work. If one were to go that rout, it may make more sense to print a mold and make the part in composite, perhaps filling with “forged” fiber or leaving it hollow.

Electroplating is generally very, very thin, on the order of microns, maybe up to a couple thou. That’s far too thin (much thinner than aluminum foil) to add a noticeable amount of strength. How about instead, you wrap the part in carbon fiber or S-glass prepreg, vacuum bag it, and cure it? If you print your part from a higher temp filament like PET it shouldn’t warp at the curing temperature.