GNOME 1 & 2: The dock is in the bottom by default. It can be moved elsewhere if the user prefers it.
GNOME 3+: The dock is wherever we think the user is likely to find it. Maybe it’s in the bottom. Maybe it’s nowhere. Maybe it’s everywhere. Verily, who can even begin to understand the mysteries of the brain?
Up to 2.x, GNOME used what was basically the MacOS philosophy: make things easy and simple and intuitive, but if the user wants finer control and power features, make sure it’s still possible somehow. GNOME 3 and later pretty much adopted the philosophy that there’s the GNOME path of simplicity and streamlining, and power user functionality is going to be removed from the core and relegated to extensions. And, of course, GNOME started requiring boatloads of memory to run, which to me didn’t go hand in hand with “simplicity”.
I eventually settled on using XFCE, because it didn’t have the bloat and still had enough customisability. Really good environment for old and underperforming systems. If I’m using a modern high performance system, I’m actually pretty impressed by what KDE Plasma is doing these days.