Companies are incentivized to sell the worse, most expensive version of a product that they can convince someone to buy. Many companies sell with huge margins, meaning there is significant slack to allow quality to increase for the current price point - there just isn't enough competition to matter. Many manufacturing companies also have complex supply chains, making this problem worse as everyone along the chain tries to maximize their own margin.

It's not at all rare for a company to sell a quality product at a low margin for some years, building up a reputation, and then start decreasing quality to increase profitability once the quality branding is established.

Or more likely consumers aren't paid enough to buy quality.