That's how they get you. First you sideload one app, you think you can stop with just one, then next thing you know you've got F-Droid on your phone, your sideloading left and right. Then before you know it, all your money now belongs to a Nigerian Prince and hackers are ransomwaring your grandma.
Yeah kids sideloading might seem fun, but it's a gateway to disaster. Just say No to sideloading.