Basic access authentication over HTTPS has clear advantages over Digest access authentication over HTTP.
Even with digest access authentication, you can actually store your passwords hashed with an unique salt (realm + username), but first this salt is guessable (this makes attacks against single users and small groups easier), and second you can't use
PBKDF2 to make hash computation harder. Also, if you chose to store the hashes in a non-recoverable format (which you should do!), you can't change the realm without requiring the clear user password.
SASL, digest access authentication even has been marked as historic by IETF. For SASL, they had an alternative (SCRAM, clearly demanding SASLPrep for character normalisation for example) they could recommend to use instead. SCRAM for HTTP has unfortunately never passed the draft status (Note that with SCRAM, user's salts aren't secret, too. The attacker can abuse the login mechanism to get salts for every user they want).
Digest access authentication can give a false sense of security. If the attacker can capture a successful login, he can mount a brute-force attack against the password.
nonce are all known values for the attacker.
Using unencrypted HTTP is, with or without Digest access authentication, not immune from MITM. The attacker may not be abled to catch the password, but they can capture session cookies, and modify content or impersonate the user.
With digest access authentication is only specified for login but not for account setup. You have to do the account setup the "usual way". Even if your code is smart and it only sends the inner hash to prevent the password to be transported in clear text, it can be modified by the attacker to also relay it to them. However, this severe problem exists only one time, at the registration. Assuming the user logs in from only a small amount of machines, you can achieve similar security using TACK for HTTPS. This allows the user's browser to only authorize the certificate it got at the first connection to the site. So only the first connection remains exposed to possible MITM, just like with digest access authentication.