I don’t know that I agree with this.
Of course it’s great to be a Swiss Army knife of design skill but to target your portfolio a little when starting out can really help with landing that first job.
Portfolios that do a little of everything but nothing really great have of course a harder time attracting attentenion.
Portfolios for young grads are supposed to tell a story, communicate quickly “this is me and what I am passionate about”.
I think it’s completely valid if the OP is worried about not having that.
In my past I have always had that red thread that I continuously returned to in portfolios and selected projects that supported this “passion pitch”.
This thread though has changed many times as I have changed direction.
Finding “your thing” that sets you apart is a journey and changes but it’s important to get that initial stepping stone.
It’s maybe a little like climbing where you grab-pull-step-push-evaluate-repeat.
Don’t give up! It’ll happen.