[caseyy]

You can actually disable the browser in a pretty serious way in iOS. First, ask your spouse/friend/colleague to set up parental controls on your phone and have them hold onto the code. Second, remove Safari through Content & Privacy Restrictions. Third, set up Downtime in whitelist mode to run all day. This way, Safari is disabled and an alternative browser cannot be installed from the App Store. If you want full control of your phone back, you'll need to ask your spouse/friend/colleague for the code – totally doable but now it's pretty difficult to get around the restrictions.

Something similar should exist for Android with regard to parental controls. Though for Android, I suppose you could also just uninstall/disable both the browser and the Play Store through adb.

[uncharted9]

Parental controls on Android are a bit more complicated and require another Google account. I'll take the latter route. I'll just install something like Firefox Focus, which clears browsing data on exit. It will help for one-off searches or an app that launches the browser for some process. I'm not sure if disabling the Play Store is a good idea. It might cause problems with updates. Right?