Also just slow, fragile environments once they are set up.

At a previous place I worked, tests would be slow, builds would frequently break and you had to recite the correct incantation of commands to fix them again. We had a common saying: whenever someone would say their build process is broken, we'd say "ah you must have pulled master".

Environments that are fast, stable and get out of your way are a godsend. Unfortunately when working in a monolith, everyone's special build changes are shared with everyone else. Then those build changes break things.