Tether imploding isn't at all like a public company closing shop, because public companies are Real Things and have public data about sales, revenue, employees, business relationships, etc. And even the ones that implode go through bankruptcy court where their assets are doled out to debtors and shareholders.
Tether imploding would be more like a bank run, where you can see YOUR MONEY as a number on the screen then when you go to cash out, you simply can no longer access your money. Or maybe you can withdraw $100 a day, but no more. If and when that happens (or threatens to happen), everyone freaks out and tries to get their money at once - which is exactly why the banking system in the U.S. is backed by the federal government so this doesn't happen.
The higher risk is that a good swath of crypto investment is done on leverage, which can increase with the more money you have. So with $100MM and a bit of lying you can go invest 10x your money in crypto and get some fat returns - lets say you go all-in and put $1B in Tether and get an 8% return on your money - thanks to leverage you are actually making 80% return on your $100M (sample #s, but you get the idea). This works great until things blow up, because you don't just lose your $100M, the BANKS that gave you leverage ("margin") lose $900M too, so one idiot taking this gamble can have a massive impact on the banking system as a whole.
This isn't just theory either, something akin to this happened about a month ago: https://www.thestandard.com.hk/breaking-news/section/2/16880...
And that wasn't even fallout from a Ponzi scheme, but simply from: bad risk management + leverage + minimal oversight + lying. The real stupidity is that these banks have continued to provide margin loans at very low rates with loose oversight, which should remind you of "race-to-the-bottom" mortgage market that blew up housing around 15 years ago. Except now we are talking about hedge funds and billionaires and a billions of dollars being thrown into shitcoins and NFTs. So when this implodes there won't be any collateral at all to rely on.