While I think a lot of people agree with you, this is a real unpopular opinion to me. I love capsule shapes and large radii. I like my ui to feel soft, not pointy. shrug
Rounded corners do create a lot of opportunity to implement it poorly, though. I see a lot of rounded corners that aren't concentric, or worse, are inconsistently rounded (For example, I'm extremely irritated by some US highway road signs where the border is rounded but the square corners are left on)

I really like this.
I think most people have heard the "you need to work on yourself first" advice, which just feels unhelpful.
And I've always felt that people calling themselves "king" or "queen" is them being narcissistic.
But this advice nicely reframes both of those things into a really good mindset.