If there is a risk of a 10+ million dollar issue there is also some manager whose job is to overreact when they hear the announcement that someone wants to eliminate thing X, because they know that thing X is a useful part of the systems they are responsible for.
In a reasonable organization only very minor systems can be undocumented enough to fall through the cracks.
In an ideal world sure, but knowledge gets lost every time someone randomly quits, dies, retires etc.
Stuff that’s been working fine for years is easy for a team to forget about, especially when it’s a hidden dependency in some script that’s going to make some process quietly fail.
The OP explicitly said "if you involve all required management", and that is key here. Having a process that is responsible for X million dollar of revenue yet is owned by no manager is a liability for the business (as is having an asset in operation that serves no purpose). Identifying that situation in a controlled manner is much better than letting it linger until it surfaces at a moment of Murphy's choosing.
> Stuff that’s been working fine for years is easy for a team to forget about
That's why serious companies have a documentation system describing their processes, tools and dependencies.
The basic premise was it’s no longer obvious if a system is still doing anything useful. If the system had easy to locate documentation saying everything that used it then there wouldn’t be an issue, but that’s very difficult to maintain.
Documentation on every possible system that could use the resource would need to be accurate, complete, have someone locate and actually read it, remember, and communicate it with someone in a relevant meeting which may be taking place multiple levels of management above the reader here. As part of that chain when a new manager shows up and there’s endless seemingly minor details, so even if they actually did encounter that information at some point theirs nothing that particularly calls out as worth remembering at the time.
That’s a lot of individual points of failure which is why I’m saying in the real world even well run companies mess this stuff up.
In a reasonable organization only very minor systems can be undocumented enough to fall through the cracks.