To me, blitz is good for short tactical and opening repitore practices. Daily is for doing your best as well as rapid. Online ratings do matter and have a lot of value, but they cannot accurately describe your strength perfectly.
Going to OTB tournaments is more fun and actually helps to get you better faster. Look at my games, most were just luck. Nothing new to me. At least blitz can help me to find tactics in a consistent and a fast pace. Good riddance you mentioned that, some people do bullet chess to use as an indicator for their ability, they often lose easily and offer a rematch and just play for time, it's not healthy chess. It's far worse 
Many bullet players often treat fast games even to blitz as serious chess, it doesn't work this way, no good players wanting improvement will do that. Puzzle rush is ironically a good practice and is fun as well 
It is a pretty good indicator of your current tactical ability, which is half the picture. In a long game, some other characteristics have relevance even to tactical ability, like thoroughness, and playing sufficiently sound chess to create tactical opportunities. But if you stink at blitz, any tactical successes you have at slow chess are just using other strengths to compensate.
It seems that nowadays there are a lot of players that grow up on internet chess and develop skills for bullet and blitz but aren't solid enough to be nearly as good at slow chess, but that doesn't mean that blitz tells you nothing.
Using your example, if someone can't spot the tactics here in a blitz time frame, they aren't likely to be able to spot more complex tactics that build on these patterns in a long game. Its related.