The Blocksize wars disproved this in several ways. There were DDOS attacks against the big block nodes and because fewer people ran them, it posed a significant threat to the big block network. Also, the big blockers failed to persuade users (I.e. noderunners) to hardfork which is why the miners did not follow. Finally, if there is a concentrated attack by governments or other bad actors, Bitcoin is a lot more secure if we have 100,000 copies of the blockchain instead of 10 that the US can just dronestrike.

Also, if you are going to push an altcoin at least have it be a decent one like Monero, Bitcoin Cash has no redeeming qualities.