Will Elite Boutique banks ever try to become a traditional bank like Bulge Brackets?

No, there’s a reason boutiques are focusing on private capital advisory.

The US doesn’t want retail banks lending to corporates to keep risk away from consumer.

The rise of private capital and private capital advisory will take over corporate lending.

Cuz then the office will be filled with back office people

bc not everyone wants to be goldman ballsachs 

Cuz they don't want to hire girls

Also curious about this

Much more prestigious to be a small pack of hyperborean hunters than a village of back office weenies

They're very different business models. EBs have always won on expertise and advisory vs. BBs that win on a combination (top tier win with some advisory and expertise, but many lead with the balance sheet to win mandates). The margins are better on advisory (M&A, fund raising, restructuring, etc.) than ECM and DCM, generally speaking. The work is certainly more interesting in my experience. 

I think it could be due to the niche set of capabilities they offer clients. Sure there is profits from corporate banking and other services traditional banks offer but it would limit the ability of the firm to pursue certain opportunities due to conflicts of interest. Since there are already well established traditional banks with extraordinary balance sheet sizes, it doesn’t make sense for boutiques and elite boutiques to enter a market with dominant players and fierce competition (the difference in scale would be a massive obstacle to overcome). Pursuing niche services and offering specialized services focused around M&A, private capital raises, restructuring etc. offers a chance to maintain leaner operations, hold a higher standard of service and pursue mandates traditional banks can’t. The business model also means they aren’t exposed to risks associated with defaults and managing cash reserves in the case of bank runs since they don’t engage in lending. There’s been a ton of bank failures in the United States in particular relative to other developed countries due to the large risk appetites of banks in the market.