That means local companies are forced to spend money to avoid product issues. But Chinese companies can get away with selling known faulty goods.
The reality is that it isn't just a Temu problem, "free trade" with countries that do not have the same rules is necessarily imbalanced. It seems crazy to me that we impose very stringent rules inside the EU for many things and then allow anyone to import stuff from a faraway country that doesn't have to follow those rules.
China has been cheating by definition for many years now and it's just now that people are reacting because it's now clear we have exported all the value creation process thanks to a lack of protection for inside actors...
Importers are also bound to the certification rules. For example when I buy the weird canned beverage from the Chinese restaurant in the middle of campus the can itself is of course intended for sale only in China so it's full of typical Chinese tropes - but the rules say you can't sell this if it doesn't obey rules so the importer sticks the minimum amount of extra info, in English, to every single can.
This reminds me of Americans thinking exporters will pay their import tariffs. No, your rules only apply to your businesses, you might force foreign businesses to lower prices so as to remain competitive, but, you might just not.