> If the punishment for a crime is a fine, then it only applies to the poor.

If its a fixed fine that is not adjusted in either direction for ability to pay, or which maxes out at a level which only is meaningful to the poor, sure.

If the fine is ““Your net worth minus the lesser of half your actual average annual income from legal sources for the last five years or double the federal poverty level for an individual”, it doesn’t “only apply to the poor”.

Of course, most criminal fines do only apply to the poor, but that’s not inherent to fines, but just what fines look like when the law is intended to punish the poor to start with.