Plenty of people continue to comment inline. I wouldn't have quoted your comment except it's a humorous way to make this point :-)
It may be the kinds of people I hang out with, but I have observed:
1. Business people top post; they seem to want the top post reply to be short enough to read on the phone without scrolling and want the subject line to provide enough context so AFICT they never look the the quoted message.
2. Mailing lists I'm on have a mix of top post replies and inline replies; I've learned that the top-post responders can by and large be ignored.
3. People born after around 1998 tend not to reply to mail at all. I forced my born-in-98 kid to learn to write a good email (and boy was it a struggle) but when he was looking for a job he told me it was a superpower because the folks he was competing with couldn't/wouldn't do it.