My understanding (and correct me if Im wrong @krishna), is that there’s been no specific target so far, just offering up a selection. (The markdown example is a webapp, for eg).
I think the web hosting and email have been picked up as staple/useful/most interesting for the community, and so they’ve gotten more love recently.
As for pros and cons. I think if you can offer both, it’s not that hard to these days. The email app could be a site. The webhosting could be, but would probably not be as usable…
It all comes down to maintenance really, and on that front I’d say sites are simpler (especially on safe, where there’s only one browser to worry about). But electron apps aren’t that far behind.