Couldn't we use some sort of smart contract to create distributed corporations without the need of any home or center state? Couldn't we use a virtual office?
You could probably make a "distributed business" but it wouldn't be a corporation and you would have no protection under the law. A corporation is a legal entity, it doesn't exist outside the law and the state defines the parameters of that existance. You can't just say "we have formed xyz Inc". When you file incorporation documents (with a state) the state creates xyz, Inc to be a separate entity under the law. So if you don't do that no corporation exists, and while your business may operate outside the state YOU (as a potential owner, employer, or investor) can't operate outside of a state. Maybe someday but not today. No matter where you are YOU fall within the scope of a state.
Why does that matter? Corporations (and other legal constructs like LLC, limited companies, limited master partnerships) exists to decouple the business from its principals (owners, investors, etc). The incorporation process creates a new entity (hence the term corporate personhood) and this entity legally distinct from its owners.
Why would you want to decouple the business from ownership of the business?
A corporation can file its tax returns, own assets, incur debts, be sued, etc separate from its owners. That is the whole point of a corporation. If you own shares in google and google doesn't pay its taxes you as a shareholder have no direct liability (although the share price might decline). Google is a distinct entity from its owners. Now on the other hand say your "decentralized company" doesn't pay its taxes. Under the eyes of the state the "decentralized business" doesn't exist. YOU own it, YOU (well all owners jointly) are liable. The same thing would happen if customers sued "the business". Under the law the business doesn't exist as a distinct entity. The lawyers of the customers would sue YOU personally which means all your personal assets remain liable. If the "company" borrows money well in reality as an owner YOU are borrowing money. When the company defaults on a loan, the creditors will sue you directly. Starting to see the picture.
Simple version
1) States makes laws
2) Laws are what make a corporation.
3) Corporations only "exist" with #1 & #2.
4) If no corporation exists then law will simply see the business and the owners as the same entity.