They don't, though. Sony, like many other companies, makes products for developing nations which are not sold in more affluent Western countries. ("World" products)
Trying to buy replacement Bluetooth earphones in India really opened my eyes on this one. The store I was buying from had a strict NO RETURNS policy, but still bent the rule when the headphones weren't iPhone compatible (scratchy distortion). After opening two more pairs of Sony with the same problem, they decided to stop and just gave my money back.
This wasn't a budget model - it's a model which you'll never see in the US or EU. Their products aren't just differentiated by country of manufacture, but by the intended market. Depending on brand name isn't enough.
As you pointed out: manufacturing standards vary factory to factory and region to region, and quality issues abound in newer manufacturing regions that lack the crazy competitive environment China has (a thousand pots et al).
Counterfeit PPE really revealed a lot about boys these factories operate. Very hard to verify ownership reliably.
But for context I’m basing part of that opinion on conversations I had with factory owners I’ve done business with in some of those countries running import/export. Many Chinese manufacturers see the conflict between the US and China as bad for business and have optioned third party countries to continue doing business no matter what happens. They’re very smart people.
If you buy stuff directly from a Thai company that you never heard of before just because their product was the cheapest, you'll have to do your own testing and will likely discover some sharp edges.