Looks like at least some merchants are saying they can't get enough cents, and they're pushing for Federal legislation to allow rounding to the nearest nickel (because there's currently a patchwork of local laws). https://www.convenience.org/Media/Daily/2025/1/1/2-NACS-Urges-Congress-to-Address-Penny-Shortage_GR
If a retailer didn't have to keep spotless records for tax reasons they could easily just round up OR down. Who's really causing problems with this