{Till some time back|Till few years back" very few bothered if your website was using SSL or not. Infact the term was not known to many and very few knew about the trusted seals offered by security companies. If you had an SSL certificate you were considered to be someone who was overly cautious about client security.
This all changed with a Feb 2018 when Google came out with a update for Google Chrome and on its search engine prefering ranking to websites that were protecting their clients via HTTPS.
Google Chrome and all the leading browsers like Safari, Firefox, Edge etc started marking websites which were not using SSL more info as insecure.
Need to know why you need an SSL?