Isn't Bitcoin absolutely terrible at transactions, though? It's too slow to ever be used as a cash alternative. Why wouldn't an alternative cryptocurrency fill that void then leave Bitcoin with no actual value at all?
My comment was more referring to cryptocurrency and the blockchain concept in general, I probably should have been more clear.
You are right that BTC isn't that useful as cash. I don't think BTC will be dominant forever, there are already superior cryptocurrencies for use as actual normal currency. If/when another crypto really does fill that void and achieves major adoption, I think BTC will probably retain some value, for speculative reasons and also just because it has the oldest chain.
The energy consumption is definitely bothersome but overall I am glad that bitcoin exists.