Yes, hard to imagine she took off, if she didn't take any of those essentials. Who leaves on a trip without their car, ID, debit card and cell phone? You are right it makes no sense.
Only two ways that she would want to do it that way. One, if she had a wealthy friend willing to pick her up and then take care of her and her expenses. But I doubt that happened.
Or two, she walked out while having a meltdown, and didn't care about those things at the time. But I think if that happened, she would have been seen by others, and been found by now.
Of course the other scenarios would be that she was taken from the home by force.
I am pretty jaded, from seeing so many cases here where missing women were actually murdered by their partners or by predators.
I share your suspicions about her husband. But if the police did look at him as a suspect, I guess they did not find anything that could point to him?
And why would he leave all of her things behind if he wanted it to look like she ran off?
Did they investigate him at all? Interrogate him, search his truck ever?
You said it was gone the next day. Did you tell the police about his missing truck?
Is there a possibility that someone else took her away from the home? Could she have called someone for help, and that person betrayed her?