It was definitely more primitive, but that didn't bother us. Here are some of the things I remember.

When I started, I was coding on a 24x80 CRT connected to a serial-port switch so I could connect to several different systems (e.g. PDP/VAX). A bit later I got a 50x80 terminal with two serial ports and that was considered luxurious. I also worked on Macs and PCs, which were a bit better but less than you might think.

Related to that, lacking anything resembling a modern code-navigating autocompleting tooltip-providing IDE, people actually wrote and updated and read technical documents. Reviewing them was also a Real Thing that people took seriously. Also, books. Another commenter has mentioned Barnes and Noble, but if they even existed then I wasn't aware of them as a resource for technical stuff. The one I remember was Quantum Books in Cambridge MA (later Waltham). It was common to have a bookshelf full of manuals for various UNIX flavors, or X (the window system), or Inside Mac, depending on what you were doing. If you didn't have the book you needed, maybe a coworker did so you'd walk around and ask/look.

There weren't a bazillion build systems and package managers and frameworks. You had tarballs (or the cpio equivalent) often used with for-real physical tape, and good old "make". Automake and friends might have existed, but not near me. It might sound limiting, but it was actually liberating too. Just unpack, maybe tweak some config files, and go. Then see how it failed, fix that, and go around again until you got something worth working with.

A lot of things that seem "obvious" right now were still being invented by people much smarter than those who now look at you funny for suggesting other ways might even exist. I actually worked with folks who developed now-familiar cache coherency algorithms and locking mechanisms (now embedded in ISAs) and thread models and so on. Not much later it was distributed-system basics like leadership, consensus, and consistent hashing. These kinds of things either didn't exist at all or weren't well known/developed. And it was fun being part of that process.

It was possible to know all parts of a system. At Encore I was able to describe everything that happened from hitting a key to a remote file being written - keyboard drivers and interrupt handlers, schedulers and virtual memory, sockets/streams and TCP/IP, NFS, filesystems and block-device drivers. Because I'd worked on all of them and all of them were simpler. I was far from the only one; those were not far from "table stakes" for an OS person. Later in my career it was practically impossible for one person to understand all of one part such as networking or storage. That makes me kind of sad.

Work/life balance was, perhaps surprisingly, not all that different. Crunch time was still a thing. I worked plenty of all-nighters, and even worked nights for extended periods to have access to scarce new hardware. I had more intense and less intense jobs over the ensuing years, ending on one that was at the high end of the scale, but those were all choices rather than changes in the surrounding environment.

Compensation was good, but nowhere near modern FAANG/unicorn levels. Maybe founders and near-founders haven't seen it change as much, but for the rest of us the difference between a top-paying and a median senior/principal/staff kind of position has become much larger. 90% of developers used to be in the same broad economic class, even if some were at the low end and some were at the high end. I'm not sure that's really true any more.

That's all I can think of for now. Maybe I'll edit or reply to myself if I think of anything else later.