You can try taking these posts and post them on medium on somewhere else. Try to sell them on a crypto magazine or something. If they get accepted with the same merit and rewards then the impostor syndrome is real. You have a scientifically falsifiable way to check the real worth of your work.

If not, then you have to accept the reality that Steemit is first and foremost a gift economy. It rewards primarily social connections. Article quality is secondary. Not to say that good content is not rewarded but it is rather the exception rather than the rule.

You can even check that from the comments. Most of them are irrelevant or superficial or just blatant praising in hope for a little attention. Articles that are worthy get real engagement. Again, another factual standard of measure.