It's important for customers to be able to host text files and dot directories in their root directories, most importantly /.well-known. t's an IETF standard adopted several years ago:

https://datatracker.ietf.org/doc/html/rfc8615

And with increasing importance is the /.well-known/security.txt which is soon to be an additional IETF standard (https://datatracker.ietf.org/doc/html/draft-foudil-securitytxt-12) that already many companies have implemented.