STOVL aircraft including the F-35B never hover during normal operations except for the last few seconds before landing. It burns too much fuel, and depending on how much weight the aircraft is carrying (fuel plus ordnance) there may not even be enough thrust available.

The point of the person you responded to was that STOVL aircraft can fulfill the requirement of a close air support (CAS) platform of being able to take off from hastily constructed airstrips, rather than being limited to carriers and large bases, often far removed from the area of operations.

Well that was the theory but it's never really worked out in practice due to security, maintenance, and logistics obstacles. Aircraft in forward bases are too vulnerable to mortar attacks. And all the fuel, parts, and ordnance has to be brought in by truck convoys or helicopter. It's just totally impractical.

It’s impractical in a setting like Iraq or Afghanistan, sure. On the other hand, if the Marines were to land on one of the Spratly Islands or on the coast of Norway, they could construct an airfield and have the Navy supply it from the sea, freeing one of the carriers or amphibious carriers to be redeployed elsewhere (or perhaps just adding to the local airfield capacity). Being able to base and operate STOVL aircraft days or weeks before heavier aircraft can be deployed there provides a significant advantage.