Chrome's chrome://extensions/ say "Warning: Google Chrome cannot prevent extensions from recording your browsing history" when enabling the [x] Allow in incognito. It seems to imply that uploading the history elsewhere cannot be prevented. Technically, why is this not preventable? Is it not possible to add a switch [x] Prevent extension from sending data to external servers?
Basically all extensions have the "Read your browsing history" warning. The concern is that I have no idea which extensions are possibly sending away data about everything I do on the browser, selling all my web behavior to 3rd parties.
https://discuss.howtogeek.com/t/warning-your-browser-extensions-are-spying-on-you/12394 names a few bad extensions, but certainly there are many more. https://motherboard.vice.com/en_us/article/gygx7y/your-anonymous-browsing-data-isnt-actually-anonymous explains the simple techniques which may make all your web history virtually public.