Overlay Scrollbars
GNOME Terminal is the only core app still using static, non-overlay scrollbars. This looks clunky and makes it feel dated compared to other Terminal apps (such as Tilix and elementary Terminal).
Tilix (left) and GNOME Terminal 3.30 (right), note the very visible scrollbar on the right side in Terminal:
In the interest of bringing Terminal in line with the rest of the platform it would be good to move to overlay scrollbars.