Are parents convinced to buy Minecraft?

I know there are a lot of people who have asked such a question, but have not found an answer that helps.
The thing is, my parents think that if they buy me a game, I would only play that game all day (Minecraft in this case). I would only do this for a maximum of 2 hours. Play in the day! I'm not just saying this to buy this, I also know that sitting in front of the computer too much is bad.
Do you have any ideas how I can convince them that I wouldn't just play Minecraft all day?

Then explain to them that you only play for 2 hours ^^

If necessary, you can even simply put the watch on the handd so that it rings after 2 hours and the end.

Why buy? If it's for the PC, then just download it for free?! There are enough videos on Youtube that show how you can download the full version for free.

Isn't that illegal then?

Why should it be illegal? Steam, for example, is just a company that sells games to you. But there are also people who make it available free of charge. Do you need to know if you want to spend money or get it for free