My next go-to tool after Linpeas is pspy which "allows you to see commands run by other users, cron jobs, etc. as they execute" [1]
This reminds me, I had hopelessly locked myself out of sudo access on a production box. This tool helped me get root again and fix a glaring docker socket privesc left there by some script that auto-configured docker among other stuff. I would have never looked at socket permissions I didn't configure,especially not after initial deployment of the server.
It has the annoying side effect of creating pentesters with a phobia of automation.
The OSCP places a premium on hand jamming commands and doing everything manually, banning automation, because its trying to test if you understand the fundamentals.
Out in the real world, automation is encouraged. The goal is efficiency - getting the job done within the timeframe allowed by the client. Doing everything manually is horribly inefficient when you are on the clock.
It does annoy me that people take the wrong message from the OSCP, you should be automating away as much as possible so you can spend more time making novel discoveries and giving value to your customers.
The goal with most pentests is to provide maximal coverage in a time window.
They may be relevant in red team engagements, which tend to happen over a longer timeframe anyway.
It's been kind of interesting seeing things change over the years - from strictly goal oriented, to the era of the Nessus Monkey (vuln scans sold as pen tests), and then back to goal oriented but now with additional coverage requirements.
As someone mentioned in another reply it's not banned in the OSCP. Automating enumeration is actually encouraged - after all enumeration is collecting information. It's up to you as the tester to interpret the results. On the other hand, tools like OpenVAS, Nessus etc. are not permitted as they go further then basic enumeration.