> That doesn't remove the concern that one or two companies deciding to do something can be so damaging to another megacorp who isn't competing in the same space really.
Why is this a problem? If a business does something that obviated another business, that is the obviated business’s problem.
Websites and computers displaced travel agents, streaming displaced cable/satellite tv middlemen, etc. If a business suffers because they are providing less utility to customers than another business, that is a sign of a functioning market.