In all seriousness....
Your first argument stated to name a country that you can just walk into. It’s harder to come up with countries you can’t merely walk into. If not for covid, you can paddle your happy butt into Canada, just make sure you sign the log book. EU is complete freedom of travel. As above, the only way I knew I crossed from NL into BE my last trip over, was the condition of the pavement and the sign. As for illegal entry, the list of nations you can simply walk over the border is staggering.
Your changing the goalpost was adding the stipulation of working and living, then adding staking your claim In a foreign country.
The argument is weak, as you cannot simply drive to another state and set up shop. There are requirements for tax purposes, rent/lease/housing, etc no matter where you go. So positioning yourself on the grand scale of nation hopping being impossible is a red herring.
Staking your claim is difficult argument to make, as that denotes walking in and literally sticking a stick in the ground for the country to give you that plot if you work it. For the most part this is dead and gone in the developed world (excluding say adverse possession) But, you are able as a foreign citizen to move into a number of countries, like states, and work there as a foreign worker. While in Japan I was earning foreign income as a US citizen residing in Japan. I had the ability to purchase real estate, and besides the flight in, I simply walked in and started to do it.