This is not ethical.. but here is a work-around. On Android devices, install the (free-and no ads) 'NoRoot Firewall'. Then it takes some minutes to get used to it, but you ONLY 'Allow' connections that the game needs to operate (e.g. everything that goes to port 443 is an indicator, or everything to/from Akamai, AWS, Azure, Cloudfront), and 'Block' everything that goes to port 80 (which usually is AdJust, doubleclick etc.)
It takes some trial and error, but eventually (in 1-2 minutes) you will be able to have blocked out all the ads by simply not allowing connection to download the 'ad content'.
Yes, the developer made free game and expects to be paid (via ads)
No, the developer and his/her/their ad partners don't have the right to violate your privacy when you (or your kid) play a game.