The archaic forms seem to induce many poets into using archaic language (perhaps because those forms were initially evolved in an era of "whereto"s etc.).
I can see the appeal, too, since a huge chunk of the best poetry written was written in those forms. But the forms are exhausted.
Also it's very hard to write formally structured verse, especially spreading sentences out over stanzas, that don't use filler words/redundancies/clunky rhymes/convoluted grammar, etc.
English is rhyme poor, which is one of the factors that probably made free verse inevitable.
I wonder if something like this applies in the case of rap music, too, where the constriction of rhyming Line A with Line B meant rap had to evolve out of that straightforward "bars" mode?