Why does God let bad people succeed while good people suffer?

This isn't a new complaint. It's old enough to have its own psalm.

Psalm 73 opens with someone admitting he nearly lost his faith over exactly this: watching arrogant, dishonest people prosper while he tried to live honestly and got nothing but trouble for it. He doesn't pretend the unfairness isn't real.

His turning point wasn't an explanation. It was perspective—realizing that visible success now isn't the same as things being right in any lasting sense, and that appearances can be temporary in ways that aren't obvious from where you're standing.

That's not a full answer to why God allows this timing. Christianity doesn't claim to fully explain it—only that final judgment is real, and a person's apparent standing right now isn't their final standing.

That can sound like a distant consolation when the unfairness is right in front of you. It's meant to be a real one, not an easy one.