Another way Chrome could address the problem of extensions having too much access and power over users' browsing data would be to make it easier for extensions and users to specify a list of domains that the extension should be active on.
For example I use an extension called Library Extension[1] that will load matching results from my library when I"m looking at a book from Amazon.
Library Extension requests permission to read and change data on all sites that I visit. Their FAQ explains that they request data on all sites because it would be too difficult for them to add more sites in the future [2].
I'd be a lot happier if I could tell Chrome to only run this extension's scripts on Amazon domains.
[1] https://www.libraryextension.com [2] https://www.libraryextension.com/frequently-asked-questions
Extensive discussion: https://news.ycombinator.com/item?id=18973477