If loss of a tool = loss of your skill & knowledge, then that tool isn't an asset, it's a liability. You're signing over your ability to do business to whoever sells & maintains that tool.

This reasoning resonates with me.

It also made me think about the presentation Peter Van Hardenberg - Local First: the secret master plan where he describes woodworkers making their own tools, called jigs, that help them build better.

Perhaps it is a good exercise in software to let go of a tool that we use and see if we can still do our job. And perhaps that might even lead to us thinking about and building new tools?