For Mac, yes and no. IIRC you don't need a developer's license to build and sign software for yourself. But you do need one to distribute pre-built software.
You can still run unsigned software, but you need to approve 2? prompts, and also allow exception for every executable by going to Privacy & Security tab in settings.
IIRC there is a CLI command for achieving the same.
You can’t run unsigned software on Apple silicon. Note that when you build your software if you use Apple’s tools it will inject an ad-hoc signature into the product.
You very much _can_ run unsigned software on Apple silicon. At work my department has a bit less than 50 engineers with Macs (M1 to M4) and nobody complained that they can't build and run our product (using GCC from Homebrew, not Clang from Apple). But it involves some jumping through hoops, yes.
As mentioned above you have to approve the binary two times (at least), being careful the first time because the dialog popup offers to remove the binary. Also since our product has some networking to do one has to mingle with firewall settings to allow the binary to do the networking.
The signature that gets added is vaguely a hash of the binary. You probably want to look at the UUID that gets injected into your binary instead of this.
IIRC there is a CLI command for achieving the same.