We have no money for specialist ships. In any case, air defence
destroyers and frigates are generally multipurpose vessels.
However, it must be said that anti-submarine vessels tend to be
very dedicated ships because they are designed from ground up to be
silent, along with all that volume for equipment and the towed
sonar array.
In any case, general trend is towards general purpose ships. The
Russians are doling out some new general purpose frigates too.
Quite nice ones actually.
There are the Bedoks which are specialist vessels.
Whatever anyone wants, the Formidables are already in service.
As to air defence, that's the domain of the RSAF.
Agree about the trend though. The LCS is an example of modular
fits which goes a step further as in you only carry what you need
based on the intended role. So its not really multi-role but
changeable roles.