> Because the shares aren't in your name, broker-dealers can lend them out to hedge funds shorting the company you're investing in.

This is part of how they absorb the fees inherent in trading. Or you can use a brokerage which pays you part of what is made for the loaning-out, and doesn't absorb the trading fees.

Or just don't worry about it, your chump-change investments being lent out doesn't matter.

> The shares can also vanish if the brokerage goes under.

https://www.investopedia.com/terms/s/sipc.asp

Your brokerage firm made you agree to a bunch of documents explaining their SIPC insurance, where the assets will be transferred if they go under, etc, etc. It's not their fault if you just clicked through and ignored them.

Stick with the various major brokers and expend your effort worrying about lightning strikes and sharknados.