TBH. For strictly PPC ads...
I'd balance how much fraud you're actually seeing with the cost of onboarding a new tech service.
Google does a decent job of blocking fraudulent clicks on search ads already - and you can spend the saved money testing out more keywords and markets.
For non-PPC ads (display/social), though, I'd 100% recommend using one. I've had good experience with DoubleVerify. Sure there are other great ones.