Browser extensions would be so much better with transparent, fine grained capabilities.

Manifest v3 has this by allowing you to grant access on clicking the extension's toolbar button, rather than all sites all the time.

The trouble with that is plenty of extensions legitimately need to run on all sites all the time for the user to get the value they want. Ad blockers, coupons for all stores, etc.

I think Firefox Desktop (but not Mobile) has this for all extensions but I'm not able to check right now

That feature isn't a v3 exclusive.

Source? Firefox docs suggests it is.

>In Manifest V2, host permissions are defined in the manifest.json keys permissions or optional_permissions. The host permissions defined in the manifest.json keys permissions are displayed to the user on installation and granted to the extension permanently.

>In Manifest V3, host permissions are defined in the host_permissions and optional_host_permissions keys. With Manifest V3 extensions, users can grant or revoke any host permissions on an ad hoc basis.

https://extensionworkshop.com/documentation/develop/manifest...