But yes, it's possible you are sufficiently outside the grain that you don't have any obvious tells about your social class. And, of course, a dedicated confidence man could fake enough of them to fool enough people enough of the time.
But that would be the exception that would prove the rule. And even if they were publicly available, you have to be deeply pathological to be looking up the tax records of your acquaintances, I can't expect that to be a regular problem in Sweden.
I save more than most and spend more on things like gear and vacation. Nobody knows unless I allow it to be known. Among my peers (coworkers and friends from places I've lived), I easily live in the area w the most poverty. I prefer to keep my income level private. If it were known, it would likely change the nature of my relationships. Worst would be the nonproft where I occasionally help the same ~20 people, most in awful financial situations.