If a business opens a 50 BTC channel with another business, and they transact with each other because for example that 50 BTC is the amount of wholesale goods a business like Walmart purchases from say generalmills in cereal every year, then yes there really is no reason not to use the lightning network for that. 

The big important transactions then, would be channel opening and closing transactions

nerd2ninja

bitcoin

In the beginning of my journey into Lightning people often said that Lightning will be the every day money for buying a coffee in the morning and Onchain for big important transactions like big business transactions or buying a house or maybe even a car 

However, I don't think this makes sense anymore. There is no reason to do anything Onchain because one can do anything on Lightning (besides channel opening/closing).

There is no reason the ECB and BOJ exchanging tonnes of Gold shouldn't be settled on a Lightning node. (Hypothetical example for "big transaction" - think of something else big if you don't like this example).

I say: All Lightning everything.