Don’t you need an Apple developer account to get certificates to sign your stuff? If so that might explain it since that would be… what $300 a year? On top of likely having to go through the whole Apple Store acceptance process.
I’m too unfamiliar with Xcode to know much about it. Do you need it to release software for macs?
I’m not sure how Apple gets away with forcing people to pay $99/yr to be able to let people install software without getting a warning. I guess it’s a minor issue. I have added a few installs to my “yes I really want to use this software” list on my m1 air, but I still think it’s a little bit silly. It’s obviously some sort of security feature, but Apple isn’t my mother.