We're doing this revolutionary war out of foppery and whim.
To be fair, Britain never suffered any setback on the level of Austerlitz, Jena, Auerstedt or Friedland so there just wasn't that urgent need for reform in the Army, especially since the Navy could be counted on to pick up the slack.In those times, the men who fought were the lions, the men who led them were the sheep. At least Prussia got rid of it's "Offizierkauf system" (Purchasing of officer ranks by high nobles) after Von Moltke took over as COS. The British kept it far longer, saddling good fighting with often inept or cowardly leadership