They all work by putting a bunch of stuff on a plane or boat to the US, then using something like USPS for domestic delivery. They all differ slightly in when packaging is done but this is very minor compared to the impact of production itself, if the environment is what you're concerned about. Amazon has to maintain domestic warehouses and a rapid delivery service on top of bulk purchasing the exact same items you'd get at AliExpress or Temu - and pay and maintain American workers that have a much larger environmental impact.

OP was talking about avoiding Amazon because it logistically supports Israeli apartheid with surveillance contracts, so it's definitely much better in that regard. If you want to keep getting the same stuff, save money, and not pay Amazon, this is a significant improvement.