I assume you meant "If someone doesn't have...".
In general, yes, I agree. People like to say speed can barely be trained. I don't entirely buy that. You can absolutely make speed improvements. You'll probably never turn a slowpoke into a sprint star. But you can turn someone kind of fast into someone really fast. Or someone kind of slow into someone kind of fast. One time I witnessed someone go from middling speed in early HS, think 11 mid to high 100m, to 10.3 in college. They put on a lot of muscle in the process. But that kid that can barely break 14 for a 100m will never sniff 10.xx.
With aerobic strength, I think you have more wiggle room. People in general have a bit more capacity for growth in that department. Of course some just have the genetics for it.