@ bigvjr
No, it is not mandatory. Premium Services is only required if you chose to pay the TurboTax fees out of the Federal refund.
That has an extra $44 fee for California filers who chose to pay for the product fees out of the Federal refund. If you don't want it, you have to remove it and pay upfront with credit/debit card instead of using the "pay out of refund" option.
Premium Services also includes audit protection and ID protection services in addition to the "pay out of refund" option. See the 2 FAQs below:
FAQ: What is the Premium Services package?
https://ttlc.intuit.com/turbotax-support/en-us/help-article/intuit-product-orders/premium-services/L...
FAQ: How do I remove Premium Services?
https://ttlc.intuit.com/turbotax-support/en-us/help-article/change-service-level/remove-premium-serv...
