Musk isn’t hurt by the amount of money he’s fined, but it annoys him terribly that he can’t control the situation and that his usual tools for getting his way are useless. It is a pebble in his boot that he can’t bluster, cajole, or bribe his way out of the problem like usual.
If you want to punish Musk in a meaningful way, then once the fine has been paid in full, the countdown can start. Once the same amount of time that elapsed between Twitter’s first noncompliance and the fine’s check cleared, then Twitter should be allowed back online. There will always be money to pay fines but they’ll never get the time back. Other companies will take note.