Does sibling rivalry ever actually go away? (24f) (21f)

My younger sister recently turned 21, and I honestly thought that by this age things would have gotten better between us. Instead, they haven’t changed at all.
I’ve started wondering if this is even sibling rivalry anymore or if it’s something else.

It feels like she thinks she needs to look up to me as her older sibling, but because I’m not the person she expected or wanted me to be, she’s disappointed in me. Instead of accepting that, she often criticizes me, belittles me, and says things that leave me feeling emotionally drained. It feels like mental or emotional abuse rather than normal teasing or arguments.

I’m wondering if anyone else has experienced something similar. Did your relationship improve as you both got older, or did it stay the same?

I’ve also started thinking about the future. Right now, I genuinely can’t imagine inviting her to major life events like my wedding or other important milestones if our relationship stays like this. That thought makes me sad because she’s my sister, but I also don’t want someone there who makes me feel small.

Has anyone been through something similar? Did things ever get better, or did you end up accepting that keeping some distance was healthier?

Tl:dr sibling rivralry, has anyone had a sibling relationship like this improve with age, or is it realistic to accept that some siblings never get along? I’m even questioning whether I’d want her at major life events if nothing changes.