What sort of job listings or openings

You shouldn’t start freelancing if you dont have a client lined up or a network of potential clients. Job boards aren’t great as they typically are low rate contracts of companies looking to get a discount. If you do good work your clients will spread your name for you.

without whatever employer benefits

Either price it in to the contract or get coverage through a spouse. (Depending on country) you need to cover your own health insurance, vacations, unemployment, additional self employment taxes, business expenses, and risks that you have gaps between contracts.

If you make $100k as an employee you may need another $30k in expenses, targeting 70% billable hours. $185/hour × 50 weeks × 40 hours × 70% = $130k. Numbers are examples only.

We dont have long term data because e-cigarettes haven’t been used for a long time. They got popular ten years back?

For anyone looking for alternatives, I think this list is the most up to date: https://free-for.life/#/?id=domains