Our country doesn’t need a large military. We need a skilled one. We’re an island surrounded by allies. In the extremely unlikely event we get invaded, having 1 trained pilot or navy gunner will be worth more than 1000 young lads with rifles lined up on the cliffs of Dover who would rather be anywhere else.
As for weekend volunteering, I used to do that as part of DofE through my local youth centre. That, and several others near me, closed down years ago due to lack of funds. Shame that.