"Escorts have become bloated in size, cost and roles such that they can be barely afforded and certainly not sacrificed and cannot replaced until they are worn out long passed their initially planned OSD"
I was re-reading Freidmanns "British Destroyers" which details all the ins and outs of post war design drivers - it's a 2006 book and its still the same issues. When you can't afford a large fleet you finish up loading the ships you have (or are designing) with more and more roles and they get bigger and bigger. Plus the changes in accommodation, electronics etc lead to bigger vessels