Java Server Side Sticky Experiences Without Cookies

I'm seeing a similar problem, but with different nuances, as in this post https://experienceleaguecommunities.adobe.com/t5/adobe-target-questions/server-side-experiment-target-report-not-working-java-sdk-and/qaq-p/397584

The architect we're working with says that sending cookies from the client to the server is an anti-pattern, so are there other ways to ensure sticky experiences? Why does server-side Adobe Target require cookies if it's an anti-pattern?