Lots of other differences.

1. Citizens have a right to enter at ports of entry, can refuse to hand over social media accounts, etc. Greencard holders are still at the discretion of border officials.

2. Citizens can wander the world and live abroad for however long they fancy and always be allowed to return to their country of citizenship when things go awry. Greencard holders can't do that.

3. Citizens get consular protection, greencard holders don't.

I suggest you go and try out an immigration system. You have no idea.

Well, based on the state your in you can still vote citizenship or not.

First of all, not true, but second of all, thats a pretty important difference in a so called democracy.

No, you're wrong. You can lose their Green Card.

If you leave the country for more than 6 months, you need to seek prior approval, and you definitely can lose it. I was on Green Card and when I crossed the border, I was questioned by the customs officer as to why I didn't get my citizenship yet because it was 15 years I was on GC and the point of the GC wasn't to be literally permanent. I quickly got my citizenship after that just in case the same thing happened again.

If you get arrested for a major crime, you can lose your GC but you can only lose your citizenship if you lied or committed fraud at the time of your application, or if you committed treason against the government.

... no. As someone who has had both, I can tell you there's _quite_ a difference.