Maybe a hot take on Nesta's relationship

Didn't want to spoil in the title, but is anyone else upset that Nesta and Cassian are mates? I liked the sort of slow burn that developed between the two book and having them be mates seems to take away any sort of choice in the matter. I love them together, but I thought mates were supposed to be relatively rare and now all three sisters have one. Why couldn't they just be in love without it being fate or whatever