Do we need STOVL when STOL might do?

Could it be argued that putting great research effort into creating an enormously capable STOL fighter aircraft–quadruple-slotted flaps, leading-edge devices, boundary-layer control, blown flaps, etc. etc.–would be a more productive way to go than the vectored-thrust technology of the Harrier and separate lift fan of the F-35B?

The original raison d’etre for the Harrier–every runway in Europe would be destroyed in 20 minutes by Warsaw pact forces and we’d have to operate out of tennis courts and farmers’ fields–seems to have gone away, and STOVL aircraft all seem to use at least moderately prepared and reasonably sized basing or small carriers, if only to facilitate the necessary ground-support structure. (Not counting carefully staged PR demos…)

I guess the question comes down to: are we giving away too much range and ordnance-load capability to retain an unnecessary vertical-flight capability, when a fighter with seriously advanced STOL technology could accomplish the same missions but with more load and range if they foreswore the need to land (to say nothing of taking off) vertically?

Is this a job we could assign to the Swedes?