I can actually remember what's installed on my system and how it's configured in a centralised place, even when I don't touch the configuration for a few months. It's actually better for "boring" systems that I don't touch the config of much - "why is that set up like that" is a question I can easily answer. Additionally, when I do want to play with new stuff, the various tools I'm given usually let me do that and go back to a clean slate if I'm not interested, without having to deal with heavyweight containers/VMs/etc.