All enterprises users (people using them for work and not side projects) can't get the subsidized plans. I would say subsidized plans are a minority of usage?
The subsidized userbase is large enough that cheema is right to call this out this distinction for other readers.
I imagine that most small to medium sized businesses are on either individual plans or Teams plans. The vast majority of firms do not need more than 150 seats, and API rates are not sustainable for most.
People _can_ get subsidized plans for work: we use Claude Teams, $100/mo premium seat, which caps at 150 seats. Not enterprise tier, but fine for SMBs.