The Americans have better budgets which is to their advantage.

A bit of generalization…but some large private museums are well funded. Likewise, some community-based concerns. Others are strictly low budget volunteer affairs, just like the UK.
Allen, Arangos, Weeks, Yeagan, Sessions, et al. are the exceptions.

Occasionally, museums get govt. Help, the Air Mobility Command museum saved a C-119, with significant Korean War history, from the scrapper. AMC transported the aircraft from California to Dover, Delaware inside a C-5.
Nice to have friends.