Aren't you allowed to "steal" basically everything except exact code in software? Didn't the supreme court rule in favor of Google vs Oracle that Google's use

Aren't you allowed to "steal" basically everything except exact code in software? Didn't the supreme court rule in favor of Google vs Oracle that Google's use of the JDK API was fair use? Wasn't there also a recent supreme court ruling that you can't patent non-novel math (algorithms)? I'm not sure how you could be convicted of theft in software outside of literally stealing and reselling someone's non-open source code.