I read this letter in an advice column yesterday and the reply really bugged me. The woman who wrote the letter is finding it difficult to find a partner who wants an exclusive relationship and while the advice columnist gave her some advice she also, I think, gave the overall impression the woman was odd for expecting exclusivity. One reason I wanted to post it here was in the - probably vain - hope that the woman might find this and see other perspectives.
"Asking for a friend: I’m single and dating, but when I ask about being exclusive, it puts people off. When should I have that conversation?"
https://archive.is/NgxuK
It's perfectly reasonable to want an exclusive relationship. It may not be the norm any more on dating apps but it's not, as Catherine West implies, "a red flag" to expect or request this. You don't need to "reflect on your self-esteem" and try to figure out why you want exclusivity - I'd say it's a good sign that you have healthy self-esteem that you expect a relationship to be exclusive.
Dating isn't like interviewing for a job or trying out for a sports team and it's jaw-dropping that someone who styles themselves a relationship expert suggests it is. It suggests a weird ignorance of the emotional significance of relationships.