"Canada's civil service is world's most effective" is a relative measure, not an absolute one.
They didn't include things like 'program delivery', but from what I can tell, the PS does effectively deliver things generally,
despite the significant competing handicaps, restrictions and challenges put in place to actually do anything.
No sane person would try and do business like this, or build processes like what we have, but when you have 200 years of bueraucratic buildup without some kind of red tape cleansing fire.
If a lot of the handcuffs were off, we'd probably deliver a lot more to Canadians, a lot sooner, and cheaper (if from not having inflation costs added on alone).
Sure, there are hang downs, oxygen thieves and useless ballast, but probably less then you would expect with that many people, constantly fighting against internal stupidity. Honestly surprised there aren't a much bigger slew of checked out, pissed off people given how stupid some of the routine things we do are.
Cabinet could smash down a lot of road bumps, empire building, etc. The ones that are competent enough seem to get kicked out and shuffled too soon, the more useless ones seem to be doing more politicking, even if they are only qualified to be lower level public servants anyway, but somehow in charge.