It's been this way for ages, although for chrome (iirc) this is managed via hyperlink auditing [1] which allows google to track what you're clicking even though the link appears 'clean'.
The click through google redirect also allows them to track things like relevancy of the content and time on site (if you return to google SERP by clicking the back button), in-case the target site isn't using google analytics (unfortunately most sites do).
Any search engine is going to want to know what people click on so they can make their product better. For example, I just searched for [test] on DuckDuckGo and when clicking on the first result I see DDG sending a ping back:
https://improving.duckduckgo.com/t/lc?...
which contains which URL I clicked.
(Disclosure: I work for Google, speaking only for myself)
Startpage is an anonymizing proxy for Google Search, not a full search engine. Crucially, it doesn't determine how to rank results. If they decided to try to compete with Google, Bing, Yandex, DDG etc directly by bringing ranking in-house they would have a very hard time serving good results without being able to track which of their links were popular among users.
The click through google redirect also allows them to track things like relevancy of the content and time on site (if you return to google SERP by clicking the back button), in-case the target site isn't using google analytics (unfortunately most sites do).
[1] https://html.spec.whatwg.org/multipage /links.html#hyperlink-auditing
Hyperlink auditing can be blocked with uBlock Origin / uMatrix