Every single time I’ve been asked to allow notifications on the web it’s been for spamming.

Ok? that's why you have the option to disallow them!? I for one use web-apps that I need notifications from, it's a crucial feature which Apple has sabotaged on purpose for no other reason than self-interest.

If you personally don't want to use a feature, that's fine, but you're putting out a statement like that as if no one should be allowed to use that feature because some devs tend to use it for spam. It just takes like 2 or 3 clicks to remove rights of notification from a specific app, so it's not a big deal either way.

It would be possible to only enable them for Web apps you’ve explicitly installed / added to your home screen