Well you've kind of hit upon it. In between major hits at movie studios, you need ways to pay the bills. To a staff writer pulling a paycheck for basically editing to the script? Do you really need to say anything authoritative on love? Do you have anything to say? How many people have you actually been with? Between all the writers, how many people have they actually been with? Could you you compare to the great writers who have come before, who framed love with such care and timelessness, even if nobody can understand what they were saying anymore? Is the paycheck worth trying to do that?
And then, when we do put one of those "great" romances on the screen, they're quintessential in detailing the anguish of love, how brightly it can burn, but the reality is that the fallout from most of those romances is terrible. Because that was in part the point of the stories; just how wrong something can go even though it seems so right.
On the other side of the equation, we have the RomComs, which are frequently kind of lazy cash-ins. Because it's difficult to capture what that spark between two people is all about, especially when you're making up fake characters with fake lives and then trying to say something "real" about love and romance. Mostly, it's easier to try and be funny and leave a lot of the brass tack stuff in the air.
It compartmentalizes romance and boils away a lot of the considerations of real life, and that's how we like to discuss romance, separate from reality. Your job, the car you drive, your prospects in life, none of these should matter but they all kind of do. Romance can come and go but between that, there are a lot of day to day considerations, a lot of tedium. It's great when you're with a person, but you're not with them physically all the time. People got jobs and hopefully interests.