It is about care. If you care about your (new) team mates, if you want them to feel included, if you want them to be successful from the get go for their benefi

It is about care. If you care about your (new) team mates, if you want them to feel included, if you want them to be successful from the get go for their benefit and that of the team as a whole, then you can invest the time. If you don't care, they can find their own way, ask around, copy someone else's half-broken configuration, and make their first commit after a month. If you are a manager, team lead or tech lead, you likely just poured a shit-ton of time into recruiting, interviewing, hiring. Now, go spend a few hours on making sure that setup document in Confluence is updated. It is also an iterative process. For every new hire, you spend a little bit of time, and incrementally the onboarding will improve. After a while, and particularly after having not hired anyone for a while, you use that time to just refresh the already basically good materials.