Yes. I would agree that it is already happening. But I do find it curious that there isn't a serious "almost exactly the same consensus rules as btc" chain. 

No doubt it comes down to getting off the ground. 

Scoresby

What you lose with scaling with more chains is that the smaller chains will have weaker security due to a lower hashrate, but in turn they will have cheaper transaction fees.

This is kinda already happening but the other chains also have differing consensus rules, outside of the mars situation I don't know how a smaller copy of bitcoin would get off the ground while we have L2 solutions for the main chain.

bitcoin

Should Mars have its own Bitcoin chain?

What you lose with scaling with more chains is that the smaller chains will have weaker security due to a lower hashrate, but in turn they will have cheaper transaction fees.

This is kinda already happening but the other chains also have differing consensus rules, outside of the mars situation I don't know how a smaller copy of bitcoin would get off the ground while we have L2 solutions for the main chain.