No, tis a different fleet with different requirements and responsibilities to the RN of WW1 and WW2, but is still the second best in the world, and should get better when the new CVs enter service. The Type 45s are closer to cruisers than destroyers if they take the best option for them; the 155mm gun plan is good. Of course, one would like to see it bigger and more powerful, but these are positive moves nonetheless.
No other nation could have fought and won the Falklands War, save the US, and the RN has arguably gained in strength and quality since then.
Most of the WW1 battlefleet was scrapped as a result of the Washington Treaty; the Queen Elizabeth class, the Revenge class, the Renown and Repulse were kept, and the Hood was completed as the only one of its class.
All previous dreadnoughts and super dreadnoughts went out in the early to mid 1920s, with the Iron Dukes being decommissioned and scrapped in the period 1929-1933, although HMS Iron Duke itself was kept as a depot ship until its demise in 1946. There was a move towards a standardized 15" calibre (with the exception of Nelson and Rodney; see below)
HMS Tiger was kept for a while as a converted training ship, but scrapped in
Courageous, Glorious and Furious were converted from large light cruisers with rather heavy armament to aircraft carriers. Argus and Eagle were also converted as carriers, and Hermes was built as a purpose built aircraft carrier. A WW1 experiment, Vindictive/Cavendish, was converted from seaplane carrier back to a light cruiser.
Further battleship and battlecruiser projects were cancelled as a result of the Treaty (N3 and G3, respectively), but Nelson and Rodney were completed as 16" battleships, but to a limited compromise design that was rather flawed.
Cruisers were limited to 10000 tons, and construction on the new County class of these was entered into in the late 1920s.
The RAN battlecruiser Australia was scuttled as a result of the treaty, and the New Zealand also went to the breakers.
Operationally, the RN did blockade the Bolshevik fleet at Kronstadt as part of operations against the regicidal Red menace.