Yes, but models aren't truths, they are tools. Velocity A + Velocity B = Velocity (A + B) was a good enough model until we needed a more complicated one to account for relativistic speeds.

It doesn't mean the first model is wrong, just that it's not the full picture. I refuse to believe that Einsteins theory of relativity is the full picture.

I wonder why the speed of light is the speed of light? I feel things that are once thought of as "physical intrinsic laws" are really just results of a more complicated mechanism. So what's to say the speed of light, and velocity and spacetime in general is just the observable symptom of something more fundamental?

I don't expect us to find something faster than light but I'm not convinced the entire concept of velocity and spacetime is as fundamental and solid as it feels now.