This is great advice!
A lot of what I read here so far is either “never” or “when I get the job done.” The first answer risks burnout or imposter syndrome, while the second risks failing to grasp first principles and how to do things efficiently, salably, sustainably.
Your answer helps avoid either problem.
You aren't really a generalist if all you do is solve the problem without understanding anything, and this approach will usually bite you or your replacement down the line. Just consider solving "I need a message queue", "I need to add Elasticsearch", or gods forbid, "We need a frontend JS framework". I've been at companies where this has happened, and it's a dumpster fire weeks afterward.