You misunderstand what lemmy is and how it works.

There is no single lemmy site. Lemmy is code that can be run by anyone with the patience to do so.

Everyone that does so has what is called an instance. The instance you are using is called lemmy.world. The instance I am using is sh.itjust.works. Our instances can talk to each other freely (unless the person running it decides otherwise), but are not the same "site".

This is called federation. A whole bunch of sites using the same software to talk to each other.

In your case, when you can't access lemmy at all, it means that the lemmy.world instance is having problems.

I can't say anything definite about the communication your instance has with its users. However, lemmy world is one of the bigger instances, and that brings hassles with up time.

But, since there's only a small handful of people running the server, chances are that when there's immediate trouble, they are busy fixing the problem, and wouldn't step away from that just to say they're busy fixing it. Doesn't make sense to do so tbh.

This is why having multiple instances is a good thing. Lemmy can only go down if every server goes down. This is unlikely to happen randomly. Your best bet is to have multiple accounts on different instances. This means you can freely switch between them when there are outages.