Not from my experience. Many Windows users have anti-viruses installed, and they flag unsigned soft. I'm speaking from experience: it is cheaper to buy pricy certificate than loose big chunks of customers because of Windows Defender warnings. This is especially problem if you have software with rapid development cycle. Like I do - we got daily builds going up every couple days or so.

Also, Windows "trust system" seemingly works also on unsigned binaries. If you don't disable bunch of security settings, you would be blocked similar to self-signed certificates on HTTPS. You can go around, by clicking tiny button. Is enough users do it, software getting flagged as OK.

Certificate solves that this should be done per certificate, not per binary.

Shhh! Don't give them ideas! :)