First of all Google will not “downgrade” you. Second, yes, Google does put a certain emphasis on SSL.
And why do you think that is?
Because only SSL provides proper transport security and there is a reason why browser manufacturers require SSL for certain features.
It really is simple, if you want SSL put your site on “Full strict”, if not set it to “Off”. A certificate really is a simple thing and can be done within a matter of minutes (even more so with Origin certificates) and it is, honestly, pointless and tiring to have to repeat this every four weeks over and over and over and over and over again because someone new comes along who believes he has what it takes to run a website but doesn’t have the faintest clue of security and just follows some random security “suggestions” some random guy made in some random video.
If you want transport security configure a bloody certificate and be done with it and don’t mislead your visitors and other Cloudflare users (“most used option”).