An Auto (Free) SSL Certificate is a new feature available with cPanel for free to make website safer. This SSL is automatically given with a hosting plan. Regular SSL or Paid SSL Certificate provides the same encryption as Auto SSL.  

Regular (Paid) SSL Certificate (Extra)

Regular SSL or Paid SSL Certificate provides the same encryption as Auto SSL but it comes with additional features like warranty, unlimited free reissue, wildcard support, OV and EV feature and more. You can get a regular SSL for 1, 2 and 3 years of validity where an Auto SSL available for 1 year only.

Regular or paid SSL is any of the SSL/TLS Certificate which is offered by CA’s (Certificate Authorities) like RapidSSL, GeoTrust, Comodo, Sectigo. These SSL/TLS Certificates are charged as they are offered with some of the extra features like warranty, unlimited free re-issuance. Additionally, a different type of SSL is also offered like, DV (Domain Validated), OV (Organization Validated) & EV (Extended Validated) and other like Wildcard Certificates which are good to protect one main domain with multiple sub-domains. Lastly, these SSL/TLS Certificate comes with extended validated time length like 1 to 2 years whereas Auto SSL expires after every 90 days.

Free VS Paid SSL

1. AutoSSL (cPanel partnered, Sectigo issued) certificate is valid for 90 days and has to be extended after that. RapidSSL or other paid certificates, you get has, minimum 1-year validity

2. You can only have Domain Validated SSLs with AutoSSL, but there are Organisation Validation and Extended Validation which you will have to pay for, and the validation in those two cases is a manual process as far as I know. For eCommerce websites, OV and EV are recommended, because those SSL validations would ensure physical address and reachability over the phone for those enterprises.

3. As you mentioned, $10000+ warranty is missing. But I haven't heard an incident where a provider had to give away the warranty amount because of a breach, though.

Free AutoSSL with cPanel
Free SSL works as a Domain-Validated SSL for your website, providing you with the basic security and encryption between your visitors and your site.  Free SSL certificates fit into two categories. ‘Self-Signed Certificates’ are the ones in which there is no need for any Certificate Authority to sign them. They are signed by the issuer him/herself. On the other hand, the second type of free SSL certificate available in the market is signed by a Certificate Authorities (CA). As far as the level of encryption is concerned, a free SSL certificate provides the same level of encryption as the paid ones.
 

Paid Regular SSL 
Paid certificates are termed as the SSL certificates sold by either web hosts or certificate authority.  To equip a website with these certificates, one must pay for it. A paid certificate is issued and signed by a trustworthy certificate authority (CA) such as RapidSSL , Comodo and Thawte SSL.  You either get it directly from the Certificate Authority’s website or you can purchase it from 3rd party entities called ‘Resellers’.

Level of Trust

As mentioned earlier, the free certificates assist with domain level validation only. If one wants to get OV and EV certificates, he/she has no option but to go with paid SSL certificates. With OV & EV certificates comes visual indicators such as the green address bar and better site seals. Whereas, free SSL certificates don’t deliver such privileges. It has been proven time and time again via research that the chances of a customer buying from you increase significantly with a green address bar and well-placed site seals.