Sure, some cultures or religions might say otherwise, but at the end of the day it’s just basic ethics.
It is just semantics, but everything in our life is semantics, so words are important. “Having sex” makes it sound casual and like relationship of equals, which it is not.
Here it’s quite common that an 18 and 15 year old who are dating are being relieved from the criminal responsibility because they are considered to be close enough in their stages of development by the judge.
It may be harder to do that if it’s defined via rape. Because how would the development level of the older partner affect the younger ones inability to consent.
Personally I’d rather have this way instead of reading from the news how a married couple has the older one saying they are a registered sex offender because they banged eachother as teens.
Only if you don't understand the meaning that someone is intending to impart by using those words.
And I'd say that in this case, there should have been zero confusion, and that it was perfectly clear what people were trying to say, so the words used don't matter.