Carrier (trucking company) vetting

I’m noticing the complaints among USPS worker facebook groups piling up about a lot of the contractors/subcontractors that brokered mail loads are being picked up by some really low-quality carriers lately. I used to work at the P&DC in Philadelphia, and talking to my former co-workers there it’s the same thing. We used to have runs from the plant in Philly that would run back and forth to the NDC in Northeast Philadelphia that USPS TTOs would do, but now it’s all contractors who only seem to speak Russian. Is there nobody at USPS that knows the warning signs to look for when a carrier bids on a load they post? We weren’t doing stuff like this when I was there, what changed recently?