As long as the job can be delivered to a mutually-satisfactory state, then it shouldn't matter if it's done by an A/B/C or D team. A lot of times in software "consulting" firms, the "profit" margin diminishes or is negative the closer you approach the top levels of developer in terms of quality/seniority. So it's in their best interest to get the most out of less-senior developers, otherwise they simply don't turn a profit.
The clients though, they want to pay the consulting firm relatively the same price they would pay for a standalone developer employee, per hour. The entire industry is broken and a lot of it has to do with broken recruiting, the recruiting industry, the "consulting firms" (body-shops) that are just resellers, and onerous employment regulations that make firms prefer outsourcing to shady outfits instead of hiring in-house developers.