AI dismantles consulting scale advantage as boutiques target Big Four

TL;DR:

• The FT and City AM both report that AI is eroding the scale advantage that protected the Big Four for decades, with AI-native UK boutiques Queen’s Tower Advisory and Unity Advisory targeting market share.
• The Management Consultancy Association says smaller firms are now growing at up to 50%, while the Big Four have cut UK graduate intake and PwC’s global headcount dropped 5,600 last year.
• For UK professional services, this is more than a competitive story — it raises real questions about the future of the graduate-recruitment pipeline that has historically fed the City’s professional services ecosystem.

A confluence of AI capability and private-equity capital is dismantling the consulting industry’s traditional pyramid model, according to converging reports this week from the Financial Times and City AM. The FT’s Big Read examined the rise of AI-native challengers — including Queen’s Tower Advisory and Unity Advisory, both founded by former Big Four partners — while City AM reported that UK industry sources see the sector “at a crossroads”, with much of the industry “peddling an outdated model”.

What AI is actually undoing

Three structural pillars of consulting are under pressure simultaneously. Generalist consultants — prized for analytical ability over deep sector expertise — are most exposed to generative AI, which performs the same kind of synthesis work. The billable-hour model is breaking down as AI compresses tasks from days to minutes; clients are increasingly demanding outcome-linked pricing. And the pyramid staffing structure, where junior consultants generate billable hours that fund partner profits, loses its logic when AI does the work juniors used to handle. McKinsey now has roughly a third of its work tied to performance-based fees after a two-year overhaul.

Mark Bunker, founder of Queen’s Tower Advisory and a former Deloitte senior advisory partner, told the FT he is targeting teams that are “20 per cent humans, 80 per cent AI agents”. European private equity has committed more than €500 million to tax advisory firm WTS, which aims to hire 100 partners within five years. Alex Hamilton-Baily, a partner at executive recruiter Odgers, told City AM that consulting leaders he met “collectively thought that next year they would reduce their early-career intake”.

UK-specific stakes

Accenture’s share price has fallen more than 50% from its late-2021 peak, reducing market value from over $260 billion to about $108 billion. PwC’s global headcount fell by 5,600 last year, the Big Four have cut UK graduate recruitment, and BCG now claims 40% of revenues come from AI- and tech-focused work. For UK professional services — long one of the City of London’s defining sectors — the implication is significant: the routes by which graduates have traditionally entered well-paid careers are narrowing.

Lisa Fernihough, head of advisory at KPMG UK, was unusually candid in the FT report: “I want this organisation — us — to still exist … That’s how disruptive I believe AI will be.” KPMG has set up an “air-gapped” initiative called Project Watts to bypass normal approval processes when experimenting with AI tools alongside clients.

Looking forward

The Big Four retain significant advantages — capital, global networks, multidisciplinary scope — and may yet shape-shift, as EY’s Sayeh Ghanbari predicts. But the mid-tier consulting firms, with neither the Big Four’s capital nor the boutiques’ agility, look most exposed. The next twelve months will reveal whether AI is reshuffling the consulting market or genuinely creating a new tier of challengers.