Daughter 'introduced' us to Temu a few months ago. Everything we have bought has been good, except for the odd 'super-cheap' kitchen gadget which TBH we thought would be rubbish. The first cycling item I bought was a pair of panniers, which were less than £6 and I expected they would be rubbish! - How wrong could I be? They have a poly reinforcement liner to keep the shape, a durable weave, and I wouldn't have grumbled at 3x the price! Next was a cycling top, and it's as good quality as others on sale in UK eg Lidl ones, and only £7. Other items we have bought are for Daughter's house, the standout being the 'peanut' pull-out shelves for the kitchen blind corner base cabinet - A perfect item for half the price of
Ebay and a quarter the price of DIY outlets, and exactly the same item judging by the pictures. The garden storage containers were again a lot cheaper, larger and gavlanised steel and with stainless steel hinges and latches - appear good quality but the assembly instructions were poor and it took us over 5 hours to assemble the many parts with over 300 screws provided

For anyone who's ever assembled Ikea, these were in a whole new league! Apart from the cycling top, all the above were already in UK (listed as Temu local) and arrived within 3 days. I have no connection with Temu, and these are just my experiences.
I wonder if the 'they don't pay their taxes' and similar statements are put about by other businesses competing for trade. Similar comments were directed at Primark, citing 'slave labour sweat shops' until it was found that big-name retailers used the same production facilities. Personally I'd avoid buying safety-related cycle parts eg drivetrain, frames, bars etc and the electrical warning given previously is noted. As just about everything on sale in the Western world is made in the far East the goods are comparable to anything else available but at a reduced price as numerous middlemen are out of the process.