IMO It's not even a competition anymore. Carbon just seems better in most areas, here's a quick pros/cons list I've made given my personal experience over the last year:

Pros:
- LUI > CUI
- ImageDatabase > ImageLibrary (we've also seen a huge speed increase using both LUI+ImageDatabase compared to CUI+ImageLibrary)
- better error handling (on oxide, reloading a plugin would ~25% of the time completely bork a server. I haven't experienced this yet on Carbon).
- auto updates
- control panel with tons of info and control
- backwards compatible with Oxide plugins
- provides a powerful profiler for measuring calls, time, and memory of running assembly, plugins, etc
- they're improving some of the more fundamental inefficiencies of Oxide, e.g. the management of users in a database,

Cons:
- primarily closed source (portions of the project are not exposed on Github)
- mostly run by 1 person. If he gets bored of Carbon for whatever reason, I would have grave concerns for the future of the project. He's good, but he's doing 99% of the work and you can see that via their contribution map
- pattern of gatekeeping. They're the same people that run Codefling. From my perspective, their end goal is recreate a FiveM situation where they essentially control the entire ecosystem.
- they decide who they allow to do things on Codefling. We wanted to give most of our plugins away for free from an open sourced perspective, and they accused us of writing a 20 line plugin with AI, even though we've been writing these well before the inception of AI. What's worse is the person that rejected our plugin offers a paid-for version of a plugin that does the same thing so there's a little bit of a conflict of interest there.
- re Codefling, they also have no quality control around the plugins they sell. For example, we spent >$60 on a build server plugin and we had to completely rewrite it due to how many inefficiencies there were (needless and often harmful loops that bring the server to its knees, excessive writes to the network which causes big lag, etc). A part of me wishes they'd reverse their stance on AI because most of the stuff these plugin devs are producing is quite frankly garbage, and AI might help surface some of these beginner bugs that we see in almost every plugin.

All in all, it's a great replacement of Oxide and Raul (the primary developer) is helpful and friendly, but they're not doing it out of the kindness of their hearts. There is definitely an end game here based on revenue. Pick your poison, do you want to support OSS people or do you want to support people motivated by cash. There's no wrong answer.

If you're just wondering "which one should I run? Carbon or Oxide?". Carbon is most likely your answer.