Agree with "most" but I still think it is worth a try, I snagged a deal for 5 biz tickets for an upcoming holiday where one of the OTAs (some shop in NYC i have never heard of) went below pricing of filed fares and either thru discount or bulk fare gave us tix for $100 less than any other OTA. Tickets are fine and one even upgraded to F w the carrier, so I am not worried.

But I also had a situation where OTAs were incorrectly pricing a JL fare and none would issue at anything close to the price. So a real mixed bag, still can be worth the energy, in my one case saved $500.