Why trimaran warships failed Britain's cost-benefit test

Why did the Royal Navy not adopt the trimaran warship concept after RV Triton?

Its extra volume did not justify the infrastructure and construction cost for the roles Britain required.

The issue was suitability for British roles rather than a single fatal design flaw. A Type 26-length trimaran would provide much more internal volume, but its beam would demand larger construction facilities and dock-based launching, producing too little operational value for the added infrastructure cost.