We have the same issue.  Our groups provides domains/websites/email accounts for 15 companies, 30 domains, and over 100 email addresses.  We use some email by Securenym (SquirrelMail) Gmail, and Yahoo.  However, half of our 100 email accounts, about 50, are GoDaddy, and we had them all set to SquirrelMail.   This was apparently a CPanel decision, and perhaps not a GoDaddy decision.  See the differences between "SquirrelMail", or "RoundCube" or "Horde".  See - -

https://documentation.cpanel.net/display/CKB/Which+Webmail+Application+Should+I+Choose

In CPanel version 78 (current) they dropped Squirrel Mail.  In the older CPanel version 72 (just for example) you can choose between "SquirrelMail", or "RoundCube" or "Horde".   We may have to go back from CPanel to WorkSpace on GoDaddy, or rent our own server slice and load either CPanel version 72 or 74.  I suppose that GoDaddy had no choice, it was up to CPanel, and you and me, the paying consumers, were given no choice.