Because more spend doesn't fix a broken acquisition system. It just runs more leads through the same broken funnel, faster. The ads aren't the problem. The thing the ads feed into is.
Ad budgets follow a cruel math: the system you've got either works at $5K/month or it doesn't. Going to $15K/month makes the working parts work harder — and the broken parts break louder.
If quality dropped when you scaled, the ads aren't the cause. They're the loud microphone the cause is yelling into.
You're bidding into low-margin or wrong-fit work. More spend = more of that work.
Speed-to-lead, CSR script, scheduling friction. Hidden until you 2× the volume.
You can't kill the keyword that's losing money because you can't see it.