What's always surprised me is how certain companies live off nothing but PPC.
Like one of my main competitors is Servpro. They're a restoration company. They do virtually no SEO. No radio. No tv. No magazines. They just dump thousands and thousands and thousands on PPC..... to shitty landing pages, but somehow manage to pull a profit.
I do know they charge $3-5k more per job than we do. But their conversion rate is lower, their salesman suck (they're all untrained kids), their landing pages suck, etc. They barely have any reviews online. Yet we have tons of reviews, awesome landing pages, great salesman... and our ROI on PPC has always been shit.
Maybe you just need to be a franchise to do well with PPC... idk. SEO has always been our bread and butter it's just hard to scale.