(Clickbait title, comment if it worked below :P)
Optional, nullable attributes needlessly introduce state to your objects and needlessly makes your code more bug-prone and more complex. By default, optional, nullable attributes can and should be avoided. A very simple and idiomatic way to avoid them is to just take them out.
How many times have you come across classes like this
NOTE: Overuse of String and Int for everything is a problem all of its own, primitive obsession, but that's a different topic altogether - the topic of this post is strictly about what attributes classes are composed of, not necessarily their types