The economics
Free apps have to make money somewhere. Anonymized location data sells for around 10 cents per user per month. Across millions of users, that’s the entire business model.
The honest signal
A flashlight app asking for location is selling your data, full stop. A weather app asking is using it. The ratio of ‘apps that need location’ to ‘apps that ask’ is maybe 1 to 10.
Your defense
iOS and Android both let you grant ‘While Using’ instead of ‘Always.’ Same data when relevant, no background snooping. Set it as your default.