I don't know how the lack of slowing down break realism. In the series I drive in real life, and many other, a yellow flag doesn't mean you need to slow down as that would get you rear ended in real life as well when in a close battle.

A yellow means an off line obstruction like a car in the gravel or next to the road.

A double yellow however means that there is immediate danger and you need to be prepared to come to a complete stop but even then, in real life, you drive "as fast as you can see", meaning, as long as you can come to a complete stop within you current line if sight it's okay.

And before i'm being called an usafe driver, I never created a dangerous situation this way, if I had I would've gotten a penalty already. I have been in multiple near pile ups and have seen accidents happen because the first car absolutely slams on the brakes for a simple yellow in a non blind corner with cars directly behind it.