Should breadcrumbs be protected from indexing?

Question

Search Engine Optimization

Hello.
I analyze different sites and in some I see that the breadcrumbs are closed with tags <!--noindex--><!--/noindex-->. Some links are simply nofollowed.
In what cases is it better to close them in noindex, in which cases in nofollow and when is it better to keep them open for indexing?

Answer 1

Well, maybe there breadcrumbs lead to a basket of goods.
Why index the basket - each customer has his own.