>given twitter isn't profitable, i'd imagine its more money than they've ever made
But it's not as much money as they're making in ad sales to those phone numbers. Twitter will just see it as a cost of doing business and there won't be any meaningful change.
The purpose of the fine is not to make the business unprofitable, it is to make that particular endeavour unprofitable. If profit from violating law - fine for violating law > 0 then then any business not run by ethics will continue to violate the law because not doing so is less profitable. This does not change if the business is throwing out money elsewhere.