As pointed out already, it's just a function of sales cost and target market. If you buy a hobby class, low cost machine built to a price point with low cost labour then what is going to land on delivery is a hobby class, low cost machine built to a price point with low cost labour.
Always gets me when the usual suspects (albeit there seems to be less of them these days) throw contempt at those who buy products from the likes of Festool or Lie Nielsen, implying the buyer could get more for less with a cheaper brand. There is absolutely nothing wrong with the lower end of the tool spectrum, you just can't expect it to come with the service or expectations that come with the premium products is all. When you pay >£330 for a Lie Nielsen No 4, that cost includes paying decent wages to several layers of headcount that complete those quality checks who in turn make sure what goes out the door is something of value relative to the purchase cost. Equally when something doesn't meet that QC level, they take the hit, it never leaves the factory and is re-inserted into the manufacture process. That headcount also has rights, rights that mean they aren't guaranteed to be available eight hours a workday and they are appropriately trained with very mobile and very sort-after skills. The difference between low-end tooling and premium is more than the quality of materials and how they are put together, more often than not (and no, not exclusively) a premium brand typically values its employees as much as its customers. My point is, when you buy a premium brand you are buying and securing more than the end product itself.
The classic analogy is the makers who complain that their end customers don't want to pay what it costs to make their saleable product who then go on a tirade against tool manufacturers for not being cheaper or better.
That all said, I have to say the description given by the OP of the belt sander does sound like a horror show. I'd be inclined to contact Axi and ask them to assist. My experience of their customer support, pre and post sales (including during COVID) has been superb. I've always been assisted by people who take ownership of the query / problem. Love them or hate them, Axi serve a very real purpose in the woodworking community (amongst many others) and it would be detrimental to that if they weren't around.