Darvond: True, but when was the last time you saw a
Sierra style adventure game as well?
It really depends on what you mean by Sierra style, they had so many, but if games like this count...
http://www.gog.com/game/order_of_the_thorne_the_kings_challenge ...then it's really not been so long.
And this came out just few months ago:
http://www.gog.com/game/herou_rogue_to_redemption If you mean parser input with graphics, then I don't know, I haven't been actively following parser games, but I'm sure there are those too, although not commercially probably.
Darvond: You'll find plenty of first person Myst'em ups. Dear Ester, Jazzpunk, Firewatch, among others.
Indeed, but those are still a small subset of adventures really.
Consider this: how many of Telltale's games have been first person? How many of Daedalic's? Revolution? Pendulo? Wadjet Eye? Anything?
Of course there are games like Obduction, but overall those "mutant Myst-like games" are a minority.
Although if we count hidden object games as further developed adventures, then it's a whole new paradigm of course. But most people don't count them as adventures...