... this is a better idea than sea-steading, or better version of it rather. I've wondered why this hasn't been considered in the past. there already exists a community of 'international' citizens that cruise the world continuously, albeit generally retired.
With all the cruise industry liners sitting idle due to CoVid there will be some bargains coming on the market. You could design a moving city by lashing together a fleet of them that slowly rotates around the world on some schedule or another, maybe with the ocean gyre currents and drops anchor outside welcoming nations for commerce and trade occasionally. Then you could lash on an oil tanker to up the range for the fleet, or a container vessel and barge for commercial/industrial activities/ The engineering is already done, the modules are already built, they call them big boats.