Each unit of bandwidth is probably getting cheaper, but if you end up giving away a ton of it, it is still a massive expense.

Modern advertising enable predatory pricing without significant (or any) financial cost to the predator. There are fewer (or no) protections against predatory pricing in most markets because classical economics assumed that businesses would fail if they deprived themselves of revenue. That is no longer the case.

When it comes to bandwidth, supply is largely fixed and the suppliers (ISPs, AWS) are corrupt or would rather just collect rents. It's incredibly difficult for a new company to make inroads as well (even for a company like Google, which seems to have paused its Google Fiber rollout)