Trump has never declared bankruptcy. Certain branches of different Trump businesses have filed corporate bankruptcies, which is pretty common when starting and operating numerous diverse entities. Jeff Bezos expects Amazon to declare bankruptcy some day.
Bezos has started a real business and is trying to make money from it, and a bankruptcy would be something that while unavoidable, might not make him happy, the real goal is success, not bankruptcy.
For Trump, the bankruptcy is the plan the whole time. Open a company, pull in cash, loot the company, company declares bankruptcy, individual who took the money is at arm's reach from the bankruptcy.
Case and point - the Taj Mahal. While casinos do come and go (I mean, the Mirage was a seminal casino, the absolute top of the ladder, and now it no longer exists), the Taj was mis-designed from the get go, overbuilt, gaudy, poorly thought out and inefficient, and it had a lifespan that was very short for a major casino, let alone one with that level of investment. It was a Bellagio level investment in terms of cash - the Bellagio is still humming along and on par with Encore/Aria/Venetian still at the top of the pack.
What happened? The money being poured into the Taj from investors was spent in overbuilding it in a way that moved the money into Trump's pocket at the start. With that money circled into his pockets, the actual operations and continual lifespan of the Taj was irrelevant, to some extent the sooner it went bankrupt the sooner his hands were washed from it.
The key properties that haven't gone belly up are things like a monster hotel in Azerbaijan, never completed by Trump but a great way to launder Azerbaijani money into his pockets.