HTTPS is baseline now, not an edge. It functions as a tiny tiebreaker signal at most and is effectively expected of every serious site, so adding it does not lift you above competitors who already have it, which is nearly all of them. The real story is on the other side: while having HTTPS earns you almost nothing, lacking it costs you, through browser security warnings, lost user trust, and the friction of visitors bouncing before they ever read a word. The verdict is baseline-not-an-edge, with the absence being where the actual damage lives.
The reason it stopped being an edge is simple saturation. When secure connections were rare, having one could distinguish a site. Now that essentially every credible site runs HTTPS, a signal everyone shares cannot separate anyone, so its ranking weight has shrunk to negligible. It still counts as a minor positive factor, the kind of thing that might break a tie between two otherwise identical pages, but that is a long way from the boost it is sometimes sold as. You should not expect to move up the rankings by switching, because you are only matching what your competitors already did.
Where the calculus changes is the cost of not having it. A site served over plain HTTP triggers a “Not Secure” warning in modern browsers, which scares users off and signals neglect. That lost trust and the bounces it causes do real harm, far outweighing the trivial signal value of the protocol itself. So the honest framing is not “switch to HTTPS for a ranking boost,” it is “have HTTPS because its absence is a liability you cannot afford.” This is settled enough to rely on, though it is worth a periodic sanity check against current guidance.
Treat HTTPS as table stakes, not a growth lever. Make sure your site is fully and correctly served over HTTPS so you avoid the warnings and trust loss that come with not having it, and then expect no ranking edge from it, because there is none to expect. Spend the effort you might have aimed at a “boost” on factors that actually differentiate, and just keep HTTPS in place as the baseline it now is.