I understand some of the reason it happens - it's not a great experience to buy a product and then be unable to start using it immediately because you don't have the right cables. And there are a lot of low-quality cables out there which might have the right connectors but not actually work - I bought at least 3 different 5m DP cables before I found one that reliably worked at 4K. But surely that can't justify the literal mountains of e-waste the practice creates.
Sadly I don't think it'll ever change without regulation.