Several big law firms are likely worth over $100 billion if they ever were equity financed, but use a partnership structure for legal reasons. The same for large hedge funds, which use partnerships for tax reasons.

This list has some more traditional companies that have stayed private but have high revenue:

https://www.forbes.com/largest-private-companies/list/

Some of them would crack $100 billion valuation, but not all (eg Publix at #3 on the list probably wouldn't, but Mars at #4 would).

Here's a worldwide list with the same caveat:

https://en.m.wikipedia.org/wiki/List_of_largest_private_non-...

These lists only include companies that report their revenue for one reason or another (eg to get a loan). Many profitable private companies don't - their owners like to stay private and extract cash from the business rather than having to keep the profit in the business.

State-owned companies are another group entirely, and are often worth a ton.