There's a lot to unpack here...

Civil trials are not criminal trials, they require only preponderance of the evidence rather than proof beyond a reasonable doubt so the question asked to the jury is fundamentally different than something you could lock someone up for.

For defamation, this is a tort, not a crime. The purpose of the lawsuit isn't to fine anyone (a fine would be paid to the government rather than the victim), it is to recover damage done by one party to another, and for the most part the thing courts can grant is money. The elements of defamation are 1. That a statement of fact is said by the person, 2. That statement is false, 3. If the individual is a public figure then the statement is known to be false or is made with a reckless disregard for the truth, 4. That the false statement of fact caused damages.

Typically, the purpose of suing someone is to make yourself whole, not to get the state to punish someone for you. Therefore, for a relative nobody who is claiming to have been lied about, there's going to be a limitation on the amount of damages that can be claimed, since 5 million dollars is already more money than most people will make in their lifetimes.

There is some additional money you can ask for based on stuff like "pain and suffering", but again that's not punishment for the person you're suing, it's just that you want to be made whole and the court can't undo your pain and suffering so you pay money in recompense.

There is also a thing known as punitive damages, which is more money given to the plaintiff who is suing to ensure the defendant doesn't commit the tort again. However, even this element starts to run up against constitutional constraints because excessive punitive damage awards can go beyond what's allowable under the law.

Don't take the Alex Jones defamation case as representative of how the process works, most people aren't on trial for accusing a bunch of dead kids of lying about being dead on national television and so it ended up with an exceptional outcome.

Regardless of the size of anyone's judgement against them in a civil case, it would be a massive injustice to jail anyone over it. That's not what the civil courts are for, that's not their job, that's not how they're set up, and if you jumped from a 51% preponderance of the evidence jury verdict to jailtime that would send a lot of innocent people to jail (and even the rich deserve to be free if you can't prove they did something beyond a reasonable doubt)

As an example of the differences between criminal trials and civil trials, O.J. Simpson was found not guilty of the criminal act of murder, but was found to be liable to pay damages to the family in the wrongful death. There was enough found to pay a sum of money, but not enough to deprive O.J. of his rights by jailing him.

Another good example of the difference between criminal and civil proceedings is that the person sued may never even have to pay for the judgement in a civil case -- Insurance may not pay a criminal fine, but it can pay a civil judgement, so it's entirely possible that despite losing the lawsuit, a person who was successfully sued may never personally pay a penny. In fact, a regular homeowner may have a million dollar judgement against them but be protected by the liability insurance portion of their home owners insurance. This really doubles down on the fact that the purpose of a civil case is to make the plaintiff whole, rather than to specifically punish the defendant.

Your heart is in the right place with wanting to make sure punishments for millionaires and billionaires are calibrated such that they are actually painful in ways comparable to a poor person convicted of the same crime, but the facts in this matter are not aligned with that particular cause.

Anyway, I'm sorry... I'm always with the walls of text....