{Till some time back|Till few years back" no one 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 your website was on HTTPS you were considered to SSL for Website be someone who was overly cautious about securing website.
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 subsequently all the other browsers started marking websites which were not on HTTPS as insecure.
Need to know why you need an SSL?