>I wonder why companies don’t do this anymore. Is it something to do with the monopoly AT&T held, is it related to corporate tax structures, is it related to how easy it is to find PhD graduates who studied similar topics of interest, or is it something else entirely?

Companies do a lot less to retain employees - fewer pensions, fewer accrued benefits and perks - so it's much less attractive to train when you are assuming attrition instead.

No way...

Even guys get parental leave, now!

I know too many people that've gotten fancy EMBAs paid for by the company as retention/networking tools along with the countless others (read: majority) that don't use the annual tuition reimbursement available to all employees.