There will always be exceptions, for example for disabilities or medical conditions. Most of those exceptions will be more accessible to wealthy or influential families that can afford to pay off doctors than poorer families.

so that the politicians who send other people's children off to fight also have to send their own.

Right, because politicians always follow the same rules we do and totally wouldn't just find a way to dodge the draft.

Most soldiers in a "professional" army are there because their families are poor and they have few other options to make a living.

You're right. Many feel forced into it by unlivable economic conditions. That doesn't mean we should answer wage slavery with more slavery.

Politicians didn't send their own children when there was a draft in the US. Trump AND Biden are evidence of this

Make declaration of war a mandatory vote for every citizen. Anyone who votes “yes” (or illegally abstains) gets registered for the draft. Anyone who votes “no” is unregistered.

I know it’s not really feasible because governments need to be able to react swiftly in times of war. But these days with computers and cell phones, there’s very little reason that the government couldn’t push a “go download our secure voting app/visit this link to cast your vote” notification via the emergency alert broadcasting system.