I use F-Droid on Android and I don't use Google Play at all. I'm really glad laws exist that prevent monopolization and I'm really glad the OS is open source so that if it were to ever change I will just use a different fork.

There's no sign up or payment info required.

It works great for me. I don't pay for any apps nor have I ever nor will I, but if I did, I would PayPal/Ko-Fi/Shopify/Patreon the money to the Dev without any further sign up required.

1. It’s your SO or kid accessing it and they don’t know any better.

Teach them or dont give them devices or admin privs on them. If all else fails they are free to use the apple app store where apple will now be exposed to the broader market and set the fees accordingly.

2. You just bought something (an appliance, a vehicle, an FPV drone, whatever) and it requires you to use an app, and that app is an exclusive on the shadiest App Store possible.

I would never buy such junk that it requires an app. Your decisions are your own.

hope you like signing up with all your personal data and credit card information on app stores that make Apple look like saints, because that’s where this is headed, and sadly you’ll drag me with you.

Isn't that also a problem with Apple? And any specific app? In any case I've never signed up with any app store nor am I going to.

Because again this hypothetical thing you bought might be a family member buying it, so it won’t even be up to you at that point.

I mean, it's their device, why do you care? You can educate them but you can't make the right choices for them nor can I for you.

The way to avoid it is to get rid of app stores completely, and have users download and install apps one by one. Like that’s going to happen.

Do you mean like the way everyone installs programs on Windows and has for the last two and a half decades?