If I want a threaded mail view I can have a threaded mail view. I've been able to do it since the mid-90's in all my email clients.

I generally don't like web email systems, and GMail is no different in that respect. It's slow compared to a native client and is inflexible as hell. Generally speaking, for me, Google is about Search. Everything else they do I think is pretty lack-lustre. And then , even their search has been somewhat shite in the past few years. But I suppose that depends on what you're searching for. I can't stand useless results and I wish they'd do a better job of filtering out obviously fake auto-generated and parked domain sites.

I don't drink anyone's Kool-Aid. Can't stand the stuff.