I've lost jobs, but never lost insurance. I'd pay COBRA till I either
COBRA is only available for a limited time (generally 18 months - longer in some special cases), is very expensive especially for someone who's only income is unemployment, and frequently is unaffordable to poor people, and if you worked for a small company (There has always been a way to get insurance that wasn't tied to a job.
Not true for many people. Remember the pre-existing condition clause made it impossible for some and buying insurance on your own generally meant a very costly plan for individuals unless you were young, healthy and had a high deductible. Plus if you were poor, there simply was no plan cheap enough (no subsidies) to buy even if you could find a plan.