I have a commit of ~15bn queries/month with my DNS provider ATM, and if just one busy record has its TTL set erroneously low, it can cost an extra few thousand $ a month in overages. It’s not a great conversation to have with the CFO when that happens. Caching matters.
Unless your traffic is non-revenue generating or somehow poorly monetizable...
In any business doing proper budgeting and trying to make a profit, a few thousands in UNEXPECTED costs, is huge. It can be the difference between your department having the money for new equipment, or begging for a budget increase because of unexpected costs to get new equipment.
It seems like the problem is expecting a fixed infrastructure budget while trying to create ever larger customer engagement. Is it just modern companies that don't realize you can't count your profits until you've got your AWS invoices for that month?
It's a fixed _overhead_ issue, not a fixed _budget_ issue.
Your only way out is the built in tools to limit service in these cases or to build your own circuit breakers and implement them, or make your usage so small as to not truly require the cloud in the first place.