What about actually solving the problem instead of tricking the user into believing their data is encrypted while being transferred to you?

I'm personally in favour of Cloudflare as the simplest solution - even simpler than letsencrypt. However - there are a few caveats. They tend to hit some countries with a Captcha unless you disable it. Might not be an issue. Their "Flexible SSL is controversial as it only encrypts from client to them - not from them to the server. Personally I think this covers the most obvious threat models and is probably "good enough" for the a lot of use cases.