And both Grammarly and LastPass have had security bugs that let any website worm their way into the extension and access all the data from the extension (anything you've ever typed, for Grammarly, and all your passwords, for LastPass). Extensions with wide-ranging access are useful, and there's a reason Chrome has support for it, but they're also very very hard to get right, even if your entire business is writing a security-focused browser extension.

You could go the approach Firefox is going on mobile where there are currently six vetted extensions. As it turns out, they all need access to every website (or fine-grained APIs, perhaps). But... there are six of them. https://blog.mozilla.org/addons/2020/04/14/april-extensions-...