An SSL certificate protects your customers’ sensitive information – such as passwords, usernames, and credit card numbers – from being obtained by malicious third parties.
Customers can see if your site is protected when they see the green lock icon on their browser. SSL certificates are also one of the factors search engines, such as Google, use to determine where a website appears in search results.
By purchasing a hosting account, you are accepting the Let’s Encrypt Terms and Conditions. You can read the terms here