I think the OP means for a long time coverage was extremely scant—a very small lifetime amount was capped by most insurance companies.
I think this had to to with the mental health insurance scams of the 1980’s. These parents would have trouble dealing with their misbehaving kids. They’d get their kids enrolled in these mental health programs and the kids were basically in lockdown in these hospital wards. They could be in there for months until the parent’s maximum payout for the year was reached—sometimes up to 25k! Then they were “cured” until the new fiscal year came up.
Because of this, insurance companies wanted to cover their assets so clamped down on a ridiculously LIFETIME maximum rather than a generic yearly maximum. Suddenly all of these troubled teen programs hospitals had dried up an disappeared. You don’t hear about parents sending their kids to lockdown in the hospital the way the used to.
Now insurance programs are letting up a bit and allowing more reasonable monetary caps—yearly instead of lifetime for instance. And this is also why therapy has become much more goal oriented than it used to be. In order to get payment, people have to get diagnosed with something specific. They also have to have recovery goals that are solid and provable on record.
This has also made the Freudian analysis “decades of therapy” almost extinct. Which is probably a good thing.