Off-topic: micro transactions are just digital transactions. There is nothing micro about them. I really wish that term would just die
Probably called that because it's smaller than the transaction of buying the game
You would think so, but that’s not how the term has been used for over a decade. It has always been a marketing tool. Any in game transaction is called micro transactions. For what it’s worth most games with so called micro transactions are free. Look at https://www.pathofexile.com/shop/category/armour-effects, 100 coins is $10. there is nothing „micro“ about those prices
Now it is hard to draw a straight comparison. Gamers may spend a lot more time playing so $/h isn't a perfect metric. And some will frequently buy new games or worse things like microtransactions which quickly skyrocket the cost. But overall it doesn't seem like the most expensive hobby, especially if you are trying to spend less.