Why does Rockstar's most successful game, the one that made them the most money, have a such dogshit connection?

I'm a newbie, I've played for 40 hours, and in all that time, there hasn't been a single session without at least one connection related error. It was bearable a few days ago, but now I'm staring at a frozen green screen for the fifth time trying to start a heist after only being able to get online on the third try. It's practically impossible to play with friends, someone keeps getting disconnected mid robbery, and after every mission you have to constantly watch the connection error and wait to connect to a new session. I bought a barely working game.