Ukraine does not have many young people to send to die for Senile Man in the White House. And they really don't want to.
I explained it many times. Former USSR has had demographic problems going back to WW2.
And the problem was exacerbated by the 1990s. But Russia managed to get out of the 90s in the early 2000s. Ukraine have not.
Demographically speaking they are living in the 90s, where there were not that many fertile women to begin with (thanks to NATO invasion of 1941), but people couldn't afford having children anyway, thanks to US winning Cold War.
Russia has had last 20-25 years of decent demographics. Ukraine did not.
That's why you have pictures of 60+ years old ukro-soldiers.
In Russia for comparison. 55 (or even 50 I don't remember) years old private, and you are out of the system, can't be mobilized.
in practice, most mobilized were below 35. Officers is a different story, they can be called at older age, I heard high ranks were called at 65.