I got what I ordered. A cheap remote controlled relay. That works. Do I expect it to be waterproof? No. Do I expect it to handle it's max rated load? Maybe, I'd check how hot it was after 10 minutes.

Do I trust it to work safely in my use case? Yes.

Other than people that buy from actual specialty stores, that's basically how buying anything works these days. You use your best judgement and continue on.