I think Desantis is only banning mandates in schools and maybe state government entities, which may be reasonable and lawful, but IANAL. He's not banning mask wearing. I wouldn't like it if a governor banned mask mandates for private businesses. For exactly the same reason I don't like governors having mask mandates for private businesses. Either way, if the governor has the authority to make a mandate, then he should have the authority to ban mandates or even to bam mask wearing.