I was getting bored a few nights ago and had time to kill before going to pick the wife and kid and decided to what the hell, play some game, went for a puzzle type with a ton of downloads and reviews, and when to start, it needs GPS, camera, call, contacts and a ton of other permission. Really? And this is one of those that announce you they are going to screw with you, what happens with others I don't want to even think, that's why if you have the $, go for Apple and only paid apps, android and free apps launched a month ago are a recipe for disaster.
There are lots of apps on playstore that always ask for permission for contacts, files, camera and I think most of the sensors that is why I enabled the developer option to use "sensors off" to be able to disable all of them and no one can able to monitor my phone even I accept permission almost sensor will not work like camera and mic.
I'm using Samsung S9+ I don't know if other phone model have sensor off option in developers option.
Good first step is replacing g-store with Aurora Store, but it is best if you could use stores that have only open source apps, like F-Droid, Neo-Store, IzzyOnDroid, Droid-ify, etc. and even them be careful what you install.
I don't think its a good way to install 3rd party source where you can download apps most of them actually have malware.
If you want to download apps safely then download it to the original source if you know that if its safe like downloading Electrum directly on Electrum.org instead of downloading it on GooglePlayStore.
If its open source then instead of downloading it in Google build it from the source and download it then install.