Vastly different.

Superb return policy. Brand name products (on most things), and these brands will honour warranties when purchased from Amazon directly. No sales-pressure emails, fake promotions/coupons, or notifications on your phone (my wife uses Temu, and she gets these spam messages constantly throughout the day!).

I buy from Aliexpress, but it depends on the item. Some brands do have Aliexpress official stores, but shipping is often days or weeks or months (or never). Approx. 1 out of 10 orders I place on Aliexpress don't even arrive, and I won't be able to claim a refund for months after I've paid.

Aliexpress also likes to promote way too many sex toys and sleazy trash thumbnails when my order history has only been RC car and bike parts, and a flashlight. Disgusting how they “market” products.

I hate defending Amazon, because there's a lot wrong with them, too. But compared to Temu or Ali, they are just so much better in every way.