Why is that? In the US, I sometimes go to dinner with escorts I have gotten to know well over time, and no one at the restaurant has any idea whether or not she is a sex worker.
When it was all "legal" which was not long ago wouldn't matter and no one's business. Say a scenario for example a dorky badly dressed Indian dude in public say with a hot statuesque black SP like Seductive Crystal dining at Aix. Too out of place and stand out like a huge white dot on a black canvas. Might draw attention to authorities to bust some chops.
So what? Is the police going to start interrogating everyone who doesn't fit the stereotype of a ''real couple on a date''? They would quickly get in a lot of trouble because I know plenty of mismatched couples. And it's not even a crime to pay an escort for a dinner (and to bring her back to your place to ''hold hands and watch a good movie'' ).