> Share API isn't needed for sharing content, copy and paste worked better than share api and it was around decades ago.
Most big websites have different URLs for the same content. When you're sharing a link, you want the canonical URL, which is neutral and universal, not the URL you're currently on, which might have a session ID, user preferences, scroll anchors, etc appended to it. The share button in your browser uses the canonical URL of the site (if provided), which looks nicer and works better.
Canonical URLs are part of the HTTP spec. URLs with session ids or user preferences are faulty and should be removed. Scroll anchors are useful to share.
Share button certainly doesn't work better; I find it so undependable that I intentionally avoid it.
Most big websites have different URLs for the same content. When you're sharing a link, you want the canonical URL, which is neutral and universal, not the URL you're currently on, which might have a session ID, user preferences, scroll anchors, etc appended to it. The share button in your browser uses the canonical URL of the site (if provided), which looks nicer and works better.