“What do you mean “let”? A Christian agreed to the possibility of such trials as the way into God’s kingdom, for building patience among other virtues. Look at what happened to all the apostles, just for starters.”
By “let” I mean God had and has the power to stop all the suffering (he’s all powerful and all loving in case you haven’t heard) and yet he allowes it to happen (since EVERYTHING that happens, he wills).
So the only thing one can rationally conclude, using the most important gift he has “given” us, our brain, is ...
1. He is NOT all powerful and all loving as his true believers claim, or...
2 He’s a demonic, cruel being, or...
3. No one can know for sure whether a God exists and even less what his personality and attributes are. In other words, you’re an agnostic.
Which one do you pick?
You seem to have the wrong definition of phrases such as “all-loving”. Nowhere does God promise to act as our 24/7 bodyguard or stop us from making our own choices. Please lay off the red herrings.
You’re looking for proof and arguments. I admit I have no proofs nor arguments that I can offer you that I think will convince you or change your mind. I can’t even convince my acquaintances that President Biden is a malevolent dotard. I have my faith in Christ and that is enough for me. I know it’s not enough for everyone. I’m sorry I can’t do better for you.