It wasn't so much about refreshing the page (an artifact of how classic groups was built) as about the evident capabilities. Both in terms of editing the body and controlling header fields.Many of us were more comfortable with a Reply interface that moreNot sure I understand. Click Reply and have it refresh to a new window
Some of the redesigns presented little more than a postage-stamp text box in which to type your reply. Too reminiscent of Facebook's "Write a comment..." box, and implying too much that a reply should be minimal and without context (quoted original).
In the Neo re-design of Yahoo Groups it took forever to get them to open a decent size edit box, and to show the formatting toolbar - they initially hid it behind a button one had to click to add formatting. Even now the To and From fields are hidden behind an "Expand header" button.
In that regard Neo now has a few legs up on Groups.io - your Group Reply button offers no ability for a moderator to send the reply "From" the +owner address, nor to direct a reply to the member or to +owner rather than the group. Nor to change the Subject.