My impression is that the hassle and pain of doing this is often why languishing projects are deprecated. I can't tell you how many times I've read TotT issues

My impression is that the hassle and pain of doing this is often why languishing projects are deprecated. I can't tell you how many times I've read TotT issues or seen threads on eng-misc or elsewhere that would either talking about some new test system and how it handles crufty codebases, or how one should check for dependencies, or what might happen with some internal app that lost its sponsor/maintainer because they either transferred teams or left the company. For a while, even somewhat important things like Dory were un-maintained (after Moh Musa left Google), and lots of times it's happened that reorgs caused deprecations. Seeing how those sorts of things play out in actuality, it doesn't surprise me that unpopular or unprofitable products are killed rather than kept on life support. Lots of times, the people who would have to fight for them don't have the political will (or maybe even complete history of the product) to commit to staff allocation to keep them alive in the face of the alternative: chasing the next 10x dream.