What you are describing the best-case scenario. They happen.

What also happens is, they take operating businesses with reasonable returns, buy up all it's supply chain or it's competitors to reduce costs or enable monopoly pricing, then load the company up with debt, squeezing it into a terrible company. That is the bad scenario which people object to.

An example: https://pluralistic.net/2024/02/28/5000-bats/#charnel-house