In my opinion, it can really depend on how you write the story or how well many love interests fit into your plot, but the more you add, the harder it becomes to choose, the more branching you’ll need to add and the more frustrated a reader may become because they want to spend time with a particular love interest but are forced to spend time with another etc.
I personally love reading stories that have two, sometimes three love interests, just in case I don’t like one of them.
With that being said, I’ve enjoyed plenty of stories that had many love interests, and the only thing I found annoying was the option to customize them all every time I met a love interest. I’ve also enjoyed plenty where there is only one love interest. 
But at the end of the day, I reckon you should write however many love interests you see fit for your story because you know it best and you will write it best if you’re writing it how you want it to be.