When I was a kid (40 years ago) the firearms industry was made up of just a few big players and maybe a dozen very minor (custom or near custom) players.
Today, CNC machines and other milling advances make anyone who desires to be a firearm manufacturer a player. This has been a marvelous development for the 2A, as it really spreads the industry out into a vast base.
If Remington, Winchester, and Mossberg were all closed tomorrow, the gap in available arms would be filled within 48 months.
Maybe, but likely at higher prices and higher levels of quality.