Straws account for a very minute amount of plastic waste but was selected because 1) one of the most often seen plastic refuse on beaches and 2) it was felt that it had the least impact on consumers daily lives and therefore easiest to live without.
Also they’re banned valid alternatives like bio plastics from PLA or PHA that would degrade much faster and be completely safe for people and other lifeforms. PHA biodegrades in less than 60 days in the ocean.