It's quite common in LWC to work with objects.
Let's narrow the scope of this blog post on Objects.
When we invoke an Apex method or when we make a REST API call using fetch API directly from LWC what we get back is going to be an Object or Array of Objects.
As a part of it, we do something as shown below.
However, it is suggested to get rid of the legacy approach and start using Optional Chaining.
It is a great tool to handle null checks in Objects.
The above code can be refactored to something like this.
You can see that this approach is a lot more verbose, easy on the eyes, and clean.
Hope this is helpful