The 2% of cases when you need the commit log (or more importantly: someone else who inherits your code...) justifies writing good messages imho.

If you make a change to your codebase, normally you know what you want to achieve and why (otherwise... what are you even doing?). A commit message is just putting that in writing... that only takes a few seconds, often less than it takes to write the code.

So it's just a good habit to have. It forces you to think more about the changes you do & why, so it makes you a better software developer. Creating any new habit always takes some energy initially, but it's worth it.