The tragedy of himbo death

It's very easy to read as "I don't find you super attractive but you seem like someone I could settle for once I'm done playing the field"

Her intent seems to be more "I don't think I could have hooked up with you and moved on because of how special you are to me" but she phrased it in an ambiguous way

I think every one earth wants to be considered hot, smart, and funny. If your partner says something that comes off as suggesting you are not one of those things, it can be hurtful.

It's a backhanded and insulting "compliment". It can easily be seen as if she's saying that she's settling down and he's not her first choice, or that she doesn't see him as physically attractive but wants to have a long term relationship with him because of the "security" he offers. Pretty much almost every man that's attracted to women in some way will see this as a backhanded compliment or negging. No one wants it to be implied or told that they're not sexy or fun.

Yeah other people are pointing out ways that it could sound backhanded, but unless she said it in a pissed off voice it seems innocent and much more thoughtful than the more usual compliments you might think of.