Bitcoin maxi means that Eric Trump thinks Bitcoin is the only real cryptocurrency,
Some random idiot (whom 95% of the world don't even know who he is) saying this about bitcoin doesn't make bitcoin the only "real cryptocurrency". The fact that bitcoin is doing exactly what it was created to do (a peer-to-peer digital cash as the title of the bitcoin paper says) and the fact that altcoins don't, makes bitcoin the only real cryptocurrency!
Here is how Bitcoin Dominance often weakens altcoins and when Bitcoin Dominance increases, the price of altcoins decreases.
That's not how it works.
First of all this is not dominance, this is market cap ratio (bitcoin market cap divided by sum of all altcoin market caps). It only goes up and down when shitcoins dump and pump respectively.
This prediction by elites like them can further increase Bitcoin's Dominance, which may lead to the existence of altcoins in the future. What is your opinion on this?
Not really.
Altcoins serve their purpose as the alternative toys the traders (more like gamblers) use to make some money in the altcoin market. As long as this is their only purpose they will remain like this.
If some day the developers stop thinking about ways they can get rich and start innovating (like what Satoshi did) is the day that their product will become independent of bitcoin and will stop being used
only for trading on exchanges.