Didn't have fancy syntax-highlighting text editors back in those days. All monochrome with a tiny screen and a huge keyboard.
If it were up to me, we'd still be writing developer tools that are still 100% terminal compatible (and not just terminal emulator compat).
<insert rant about needing a mouse/>
Half my working day is spent in a terminal (the other half in a Java IDE). If I could I'd just use one of my terminals, an HP 700/96 or an old Link (like a Wyse). I wouldn't object to using an HP 2622 again, although they don't do 132 columns, which is a useful feature.
I've pushed most of my workflow into emacs (make jokes if you must), but unfortunately Slack took way their XMPP gateway and modern browsers are a necessity (for my work, at least). For a while I thought about getting a VT520 terminal for ****s and giggles (still do, actually) but pushing data over those old serial ports is easier said than done.
I had a VT220 and a VT420, but the VT220 didn't work at all, and the VT420 screen was dim to the point of being unreadable. Apparently it is possible to throw a huge voltage across the tube or something to rejuvenate it for a little while, but probably not worth it.
I've tried lots of USB to serial adaptors, some of them actually worked out of the box, and some weren't recognised by the OS. A couple of my servers actually still have serial ports onboard, which is great.
However dumping huge amounts of text over a serial connection is as slow as. I've gotten use to the blindingly fast GPU-accelerated terminal emulator I use on the Mac, unfortunately.