Everything you said could be replaced with 1910-14 as the current year and you’d be pretty close to prevailing opinions of the day.
Wars need men. Well trained men ideally, but he who has the numbers usually wins.
In WW1 It took 3-6 months to churn through the professionals, in WW2 I don’t recall off hand but we’re looking at months. In Vietnam it did take 5 years yes, but that’s not the kind of war that Europe is or should be preparing for. In Ukraine it seems likely to be around 9 months, for Russia at least (unless you’re paratroopers then 3 days).
Outside of huge technological and leadership gaps you need the bigger army to win and that’s why conscription is the necessary evil.