Why make the move to HTTPS?
#1 Google Said So
Google have given us several reasons to move to HTTPS, but the main reasons are Encryption, Data Integrity and Authentication. This just means an overall more secure site for users, which is especially important when handing over sensitive data. Bear in mind, your site may still be vulnerable to attacks and hacks, the HTTPS doesn’t solve and secure everything.
It's happening! All HTTP pages will be marked "not secure" as of Chrome 68 🔐 https://t.co/eD2RsuYudM— Google Search Central (@googlesearchc) July 24, 2018
#2 Security Warnings in Chrome
Google are now issuing security warnings in Chrome. This could cause issues of trust with visitors.
#3 Ranking Improvements
As discussed above, Google are actually admitting to ranking improvements when switching to HTTPS.
#4 It Looks Better & Helps Trust/Conversions
Let’s face it. HTTPS in the URL just looks better. We’ve already covered the trust this helps build, and this in turn can help with conversions.