In 2026, the best AI consulting firms aren't just tech vendors; they're strategic partners who embed generative AI into core business workflows. Think McKinsey's deep industry focus, BCG's rapid prototyping approach, or boutique firms like Artefact that excel at data-driven product design. These top players help companies navigate AI ethics, build custom models, and scale proofs of concept into real ROI. best AI consulting firms 2026 5