This last week I've created a bunch of listings and guess what.. Whenever we search for a DPS or two, we get literally a hundred applicants within the first minute. I don't care about meta for a lowly +15/16, but your chance of getting invited is very slim to begin with. Start creating groups like the key system intended.
That said, no it doesn't help that "sometimes you should bring the class over the player", is Ion's STATED game philosophy since BFA. Of course people are going to slot in the best class specific abilities and worship the meta now more than ever. However lets not kid ourselves, if you think you need a specific class to clear +15 you're just not playing very well.