In the past, adopting SSL (having an HTTPS URL and a green padlock icon in the browser URL bar) was an optional thing. Many of the websites did not require the extra security that SSL offers since it was not that necessary. Nowadays having a valid SSL certificate installed is mandatory for your site because search engines penalize sites with no valid SSL certificate and setups (and/show warnings adjacent to their search results). SSL is also necessary for all website users to practice since it offers your website security from threats like hackers and third parties from intercepting requests and data.
In addition, many modern site speed and performance techniques require a valid SSL/HTTPS setup. To take advantage of new, faster web technologies like HTTP/2, browsers like Google Chrome and Firefox will require your website to have a valid SSL certificate.
Check your Site Settings
It is worth it to take your time to click through all the sections in the WordPress settings menu since most of the options therein can impact the SEO of your WordPress site. Particularly, it’s worth double-checking your visibility settings in Settings-Reading, to ensure you are not unknowingly preventing search engines from indexing your website. This greatly hinders your visibility. You also need to ensure your Writing and Reading settings are all set correctly, these help to control your default categories and what needs to be displayed on your homepage for your site visitors to see. You need to also give your website a strong tagline in Settings- General, too.