There are plenty of senders that are open source, and open for input. Carbide seems to be doing a pretty good job to me at making some highly accessible tools for their gear. The right answer isn’t always to add something just because you can… I’ve don’t think I’ve seen them leave a true bug without fixing it pretty promptly. You may just be growing out of the software - it’s surely not for everyone, and is fairly limited in it’s overall capabilities, but in my opinion, that’s the only way to make it approachable. Going straight from “zero” to something like Fusion360 would be a huge barrier for many, many people. Even things like Mach3/4 can have some pretty steep learning curve (Seriously…who when just getting started with this would have any idea what “G54” means when listed as a mode? G38.2? Retract height vs safety height?)
-I- think the carbide guys strike a pretty good balance. They’re small, they’re not a $1B corporation, they’re just guys like you and me, making cool stuff. If you think something is missing, I’m sure they’re open to seeing the suggestions, but if you don’t think they’re implementing what you want, there are plenty of other places that can be contributed too, and they’re all part of the greater community.
UGS is pretty popular, has lots of features, runs on pretty much anything, and fully open. It’s been a pretty popular alternative to carbide motion, but there are others.
GRBL is already open, and is the “guts” of the machine, again, fully open.
There are lots of very capable alternatives to Carbide Create. CC has a pretty limited audience, by design. There are plenty of proprietary (vcarve) non free, open, and proprietary free-ish alternatives, depending on what you want to achieve.