I'm not sure I would have used the phrase "better suited" to describe the way Apex mechanics could play out in a non-BR format, but I know what you're saying. I agree with Eshshshss that there are a lot of people who come to BR games and then complain endlessly about every single factor that makes the game BR to begin with. They come to BR only to want to boil away all the game's unique characteristics until there's nothing left but tdm/slayer. But yes, I can still easily picture (and want) an Apex extraction mode, or a real PvE mode.
I guess in the end if I really thought that Apex was "better suited" to shorter, smaller modes then I would look at Duels and get really excited. Instead of which I look at Duels and scratch my head because I see a mode that boiled away everything this game was good at and left only the garbage that's no different than any one of dozens of arena shooters. It literally made me want to pick up a phone, call Respawn, and say "Seriously? What were you thinking?"