I tried this just now and this particularly seems to be a problem on Firefox.
On iOS (WebKit) and Chrome, Google’s search results can be copied just fine - there’s no redirector because Google uses hyperlink link auditing (<a href="..." ping="...">).
Firefox does support ping but disables it by default for privacy reasons.
Which is good, I guess, because now the link tracking is more apparent, but it does still happen and leads to a worse UX for the user.
Given Google's scale they probably don't care about the long tail of technical users such as us.