Pls correct me if I am wrong, you don't add the token yourself right? It was available in Trust wallet list of BNB and BUSD list right? I've seen similar thing with USDTs available in Trust wallet too, and they are fake, atleast not the real one.
I was about to check this again because from OP's post-mortem screenshots it's not clear to me why he chose the wrong token. Some posts later I see probably the picture a little more clear than I initially thought.
But from this quote (highlights by me):
I did not bridge anything. Both the SOL tokens and the BUSD (Wormhole) tokens are on Binance Chain, as is the real BUSD. I did not add any tokens. I merely used the swap function. When you search for a token before swap, it shows you the options. At the top it showed me BUSD but this was not the real BUSD.
he didn't see what he showed in his initial post screenshot of search result (I took his screenshot and edited in my interpretation of how it likely looked like):

My question is why did Trust wallet allow these fake tokens in their list of coins available to switch on and use? They deserved to be dragged because of this, I mean if a legendary member of this forum can fall victim then newbies can fall victim too.
If Trust wallet allows to still show some fantasy tokens in the internal swap dialog when you search the swap target even when you didn't select or made those tokens active or to be shown, it's a complete fuck-up and terrible UI by Trust wallet. And of course they don't admit the UI issue here, nor an explanation why the "real" BUSD token wasn't shown as top hit anyway. (I can't prove what OP said that the "real" BUSD wasn't shown to him; we have to believe him.)
Take my comments on this with a grain of salt because I'm not familiar with the internal swap feature and UI details of Trust wallet at all. I don't trust Trust wallet, I read too many issues with their software crap.
What irritates me most is that OP got a lame error message while trying to inspect details about the swap target token AND still proceeded with the swap. By no means I want to sound any superior here, anybody can be fooled, me included. Just want to highlight that it's likely better to stop at such red flags and investigate further rather than to deep dive into muddy waters.
I am sorry for your loss, $6000 is too much to be kept in Trust wallet normally, for me I would have move such amount into a hardware wallet.
I wouldn't put even temporarily such an amount in a mobile phone wallet as I consider mobile phones less secure and controllable, but that's my security paranoia.
Could a hardware wallet prevented this? Not sure as it wasn't a security issue of the mobile phone software hot wallet. With a hardware wallet you're still responsible to inspect all transaction details and know what you're about to sign a transaction for. If you choose the wrong swap target and don't realize this fact, then you could easily sign such a desastrous transaction also with a hardware wallet. The problem lies elsewhere.