It’s not 100%, someone else brought up Crank which has a hilarious sex scene that I wouldn’t cut and it’s vital to the plot.
Most sex scenes just have this feel of “the director wanted to see actresses’ naked and had the power of authority and money to make it happen”. It doesn’t feel fun it has an air of exploitation to it, which I’ll admit lots of porn does too, but not all. The best porn is when everyone involved likes it.
I think a sex scene in an otherwise not-pornographic film needs to be second guessed. Does cutting it ruin the plot? Could it just be implied and move on?
I just think they really need to justify it more than normally do.