Discussion: Do characters/MCs need to be relatable?

As the title says: do you need to be able to relate to a character or like them in order to enjoy a book and form a connection to it?
This is a question I ask myself quite often and that arose a few days ago because I was reading Some Girls Are by Courtney Summers. Regina, the protagonist, is someone I both feel sympathy for (she is first almost raped and then ridiculed, outcast and bullied by her former friends) and despise (she used to bully a lot of other people at her school and since I've been a victim of bullying myself, that makes it hard to like her).

However, I think that tension makes her an even more interesting protagonist. I can connect to her and the story, even though I've never been even close to her actual situation or in the kind of toxic girl-group relationship she is stuck in. I enjoyed the tension between these two sides of her and her struggle against herself and her peers.

So in general I think being able to relate to a character is not all that important to me. I don't even have to like them. It just has to be an interesting, complex character. For instance, I don't think many people like Patrick Bateman from American Psycho, but that doesn't mean he isn't interesting or that the book is bad. In some cases I find myself reading the book to a great part because of the villain (or maybe-villain).

Still, I often read in reviews that people liked a book/character because they could relate to him/her, or that they didn't like a book because they couldn't connect with/relate to/like the protagonist. I think there's also a pressure on authors to write this type of character, and sometimes I feel like it shows. For instance, the character is introduced/constructed in such a way that I feel like the author wanted him/her to be as similar to the anticipated reader as possible so they'd like him/her. If it's that transparent, it actually makes me dislike the character. It somehow feels insincere and  like I'm being sucked up to.

Maybe the fundamental question is what you're reading for. Do you want to find characters with traits that are similar to you, want to find someone who is 'like' you? Or do you want to disappear into a story populated with people who are completely different from yourself? I tend to find difference/otherness/strangeness more interesting than similarity/sameness. But that's just me, and it's not absolutely always the case. I guess in the end it comes down to the quality of the writing.

What's your opinion? Do characters need to be relatable? Likeable? Morally upstanding? Is that necessary for you to connect to the story? Or are there other elements that are more important to you in a book? I'd really like to know :)