Languages are constantly evolving. Sharing a written script encourages different dialects to borrow words from each other in their written form. Sharing a phone

Languages are constantly evolving. Sharing a written script encourages different dialects to borrow words from each other in their written form. Sharing a phonetic script would instead encourage them to also borrow words in their phonetic form. So dialects might drift closer over time. Long term changes aside, a phonetic script would make learning standard Chinese and dialects faster, so children could learn both their local dialect and the government standard (Mandarin) as part of their schooling. The main problem with a phonetic script would probably be the varying phonetic inventories of the different dialects/languages within China. I'm not sure if you could make a phonetic script that would work beyond the main dialects.