I mean, it was a joke, but also that only works if someone wants to buy them. I've bought options (not on $SPY) where I made a quite a bit of money on paper but couldn't sell them and didn't have the cash to exercise so they ended up expiring. Especially on low-volume securities a big part of the risk is that you simply won't be able to unload them if you don't have the cash on hand to exercise.
When you sell to open, there is a buyer for the order to get filled. At this point, you become the buyer to close the option if you thus desire. If you're selling puts, yes ensure they're cash secured. This avoids anything like the scenario you described.
The difference here is you're not betting with leverage. Modest, high probability returns.
If this didn't make sense and to be super clear. You described buying an option and attempting to sell it later. This is not what I'm describing. I'm describing selling and option to open