Keeping a betting log is possible for those who bet only on sports... and they can have some benefits from keeping a betting log. But for me, who likes to play almost all games, keeping a betting long doesn't make sense, I sometimes win at sports betting but lose at slots (or some other lucky-based game). Sometimes it's the other way around, I lose at some lucky-based game, and then I switch to sports betting...
I believe many people likes to play more than one game, as long as we have some balance we will play some game... which one usually depends on the mood.
If you play both, one way to easily track your expenses is just check your deposits on the casino site. Because it is quite easy to know if you are in the negative or positive side when you check the deposit and the withdrawal history on the site. Would be useless to track your betting history especially if you are also playing other luck-based games because for sure, the bets are quite long.
This is why, for me, knowing your deposit and withdrawal history will already give you insights if you are in profit or not.