Idk how you can be nostalgic for hacking things together with bash scripts.

Bringing software development practices to the sysadmin world has improved it so much.

Infra as code, no pet servers, languages that don't require massive maintenence every time a dependency or language version changes, testing frameworks.

Things are so much better then clicking around VMware, bugging the one guy that runs a bash script cron off his laptop to write a feature.