Yeah like mobile phones, and lots of other stuff.

First they are expensive and work badly, like the mobile phones in 1980-90.

Then they become withspread and are affordable, like mobile phones in the 1995-2005 (take a bit, give a bit depending where you live ofc).

Then they work perfectly and costs almost nothing, like mobile phones today.

Smartphones will go the same way, rejuvenation therapies too.

Also, any government would prefer people live longer instead of hogging up the retirement and hospital budget, and instead continue to contribute to society, so any sane legislator would pay upfront for the treatments.