It's not about if you should or should not search. It's about how often you have to do that, and how easy it is to search for what you want. It boils down to how much anti pattern a framework/ecosystem has. In this case, their default template caused me to search "dotnet core project multiple SDK", which yielded nothing, and is actually a completely wrong track.
The answer the asp.net team shared below, was instead of using the SDK attribute, use a completely different thing called FrameworkReference. Which can completely replace this SDK attribute, it seems.
Hence my question to them below was, why is framework reference not the default? Especially since it does lead to better searchability, and the template shows that one could have multiple of these per project, intuitively.
1. search Google, read few articles or posts
2. write code
3. make it compile
4. encounter bugs
5. research the bugs on yet other articles or posts
6. fix the bugs
7. ???
8. profit!