The network effects for bitcoin vs. alts are very real and already present a significant hurdle for any of them to overcome. For example, in 2014 VCs invested >$300M in Bitcoin firms vs. near zero for any alt. Currently numerous websites, VPNs, etc, that I use accept Bitcoin, none to few accept any alt. The fact is there are already network effects in place for Bitcoin vs. alts. This makes the hurdle higher for things such as Monero.