I'll note that that's not at all equivalent to v3's 'connect with psql'. v3 popped open a terminal with psql for the user in a new window (thus giving an equivalent experience to 'normal' use of psql, with the user's configured terminal settings etc.), while v4 only forwards the output of a virtual terminal to their web app (thus requiring you to keep a window open, keeping v4's server running, etc.).
I can understand why they did that (with the whole 'web first' shtick), but for me it does not provide the same functionality and is thus essentially useless.
- It didn't have 'connect with psql' that v3 did
- It added significant overhead and connections to the DB server
- It didn't have proper windowing support (e.g. panels could easily get lost)
- Shutting it down regularly required going into process manager, rather than closing the window.
These are the issues I can remember, but I've never really looked at it since then, in '20 or '21. Maybe those issues were fixed. Probably not.