People from the bottom third of the economic strata have always been high priority, but boot camp/basic and follow on training have always been the great equalizer regardless of one's background. I do not know that they screen "who did you and/or your parents vote for?" in recruiting, but maybe they do.
Not every teen is a lazy sack of crap. If I was 18, with this economy, if I wanted more than meh wages I could see housing/food/travel, plus skill training, plus medical, plus GI Bill as an enticement.
I was curious about numbers and found this (army):
What I found interesting is that medical is overmanned; every officer in medical (MD, RN, PT/OT, PA/NP) can make much more out of uniform than in. Other interesting info on here.
Another good article about challenges:
Since the transition to an all-volunteer force in 1973, there have been years when the military services missed their recruiting goals. These include 1999, 2005, and 2018 when either the economy was booming or casualties in a conflict were perceived high.
www.heritage.org
So from I what I am reading, it isn't 'just Biden,' or 'just being a fat ass', or just 'economy', it's a bunch of factors.