A question that often comes up when other learn about how much time I've spent improving my tooling and workflow: is it worth it? It's a question I ask myself as well - after all, every moment I spend working on tooling is a moment not spent on solving some other problem (and presumably there's a real non-tooling problem I want to solve).
The above image shows a respectable but wrong way of thinking about the problem - because it doesn't take into account the person you become. The two main positive changes in the tooler are learning and ritual.
The former is expected. Doing things generally teaches you how to do things. (: This kind of positive feedback loop enables one to change future tasks from not worth it to worth it, or impossible to possible. This is a weak argument though, since you also are displacing doing something else by working on tooling.
The latter is not as obvious, but you are what you do. Who you are affects which actions you take, but the actions you take likewise affect who you are - and by working on tooling, you become someone who doesn't accept inefficiencies, is not bounded by what currently exists, and solves their own problems - even problems that most people don't even notice exist. To bring up a favorite quote of mine: "Your tools shouldn't affect the way you think, you should affect the way your tools think".
Of course, it's entirely possible that the person you become is one that focus too much on ways to make solving your big problem easier, rather than directly solving your big problem. This is why we have to keep ourselves honest, and constantly question whether or not it is worth it.