I used to buy a lot from Temu

The closest thing to Amazon made in Latin America is almost the same thing, I'm talking of course about Mercadolibre.com, you can ask a refund for a product but if you do you cannot leave a review at all, and the products with bad scores have their scores and their reviews hidden, that's why is impossible to find a single product with less than 4 stars, and they have millions of them, it's as shady as it gets.

I had bad reviews been supressed by amazon several as well, so at this point I'm assuming any review system is theater.

Temu/Aliexpress/etc are for buying very cheap clothing. 2 out of 3 items fit and 1 out of 3 is decent quality. That's still cheaper, depending on what tariffs your country is charging. I wouldn't buy something where a warranty would be useful from them. Ok, maybe very niche hobby products, but then I wouldn't expect a warranty.

You really expect that kind of support from something ahipped across the globe for peanuts? Ali/Temu and the kind serve specific purposes and they do it well. I find reviews on those sites still useful, and at least on Ali there are a fair number of negative ones as well. Users tell if a specific part works with Home Assistant or zigbee2mqt. I suggest to sort by order number and not stars.

Ebay do something similar too. You can immediately provide positive feedback, but you have to wait 7 days to add negative feedback. This is ostensibly to encourage sellers to address issues to retain reputation. Sellers can also get negative feedback removed after the fact by doing refunds, etc. This means high volume low value sellers have little incentive to actually properly describe things or post correctly. A common issue I keep seeing is sellers using slower postage than paid for. You can immediately see from the tracking number, even if you wait 7+ days to submit feedback, you'll get a 'sorry' refund and the feedback is somehow 'addressed' without them going back in time and delivering it faster. Online reviews are just a sham now, Goodhart's law etc as even if the reviews aren't fake, they're encouraged or incentivised from real customers. Look up any service provider on TrustPil…

We have gotten to the point where you can't leave a bad review on aggregation sellers (like Temu/Ali/Amazon) because if you could, your competitor will for sure buy some farm in Taiwan/wherever and destroy your reputation.