I think the key idea behind inbox is that you don't have more than say 5 or 10 emails in your "to do" view. I never had to scroll. I only look at the inbox view (i.e. things I need to deal with) - and that is always fewer than one screen. If I need something from the "already dealt with" screen I do a search, never a visual scan.
This might be due to the volume of emails received obviously, but that's why I was wondering. It might also depend on the usage pattern, e.g. I reply to probably fewer than 1 in 100 emails for example.
If I had more emails, or more emails I actually had to address by replies, it might be different.
I never noticed the "images" in inbox though. Are those for things like purchases or travels that it renders differently? My emails just look like subject lines, with about the same density in inbox as in classic gmail (Quick check: An inbox email on desktop is a 32px div with 6px padding, while a gmail email is a 39px table row - so quick estimate is 5px more per email for inbox)
Yes, for some reason Inbox expands some attachments inline for me, and pre-renders some links (with a picture from the page a short summary). It doesn't seem to do it systematically, and it could be something that can be turned off in options (it didn't seem to be when I first checked). It seems to pick the most useless items for expansion (recurring bills! 150px vertically for this month's G drive bill!).
A quick an dirty screenshot-on-my-current-machine shows inbox compact emails at 60px vertical, vs 50 for the new gmail. All of the difference seems to be whitespace, the fonts are more or less identical. There's extra waste for "Today" and "This month", and with a couple of expanded pictures, I can't even fit 10 emails vertically on my screen (MB 12"). Gmail shows 20 emails in the same space just fine.
It's quite possible that if you have just the right volume of email, the Inbox format is perfect. It's also possible that most people don't mind scrolling. Me though, I like to see as much as I possibly can at a glance.
If I had more emails, or more emails I actually had to address by replies, it might be different. I never noticed the "images" in inbox though. Are those for things like purchases or travels that it renders differently? My emails just look like subject lines, with about the same density in inbox as in classic gmail (Quick check: An inbox email on desktop is a 32px div with 6px padding, while a gmail email is a 39px table row - so quick estimate is 5px more per email for inbox)