Bigest problem with loyality, to me:
- Is is pretty much the only way the AI takes cities, and also makes AI wars mostly pointless, since they are unable to hold any city they may take. In other words, is a mechanic (as many others) designed just for the human player. As a mechanic, it creates artifically some dynamism on the AI civs, and makes the game unplayable for them, maybe as an alternative to make them competent at war. Which to me makes the game boring for any player playing against the AI.
- The fact that no matter how much army you have u cannot prevent a city from rebellion, and the unit spam of free cities even without the resources to make them is ridiculous. Probably you don't remember it, but in Civilization I loyality was managed by happiness, and you could prevent a city from rebellion, by lowering taxes (remember when you could just adjust the % of the taxes you would impose on the population, and that taxes played a role on how much research you would do and how happy your citizens would be and how much army you could sustain?) and other stuff that affected hapiness like having certain buildings, or having a big enough military force on the city (with a big enough army you could prevent a city to revolt), and as a last resource by disabling the population and letting it starve. It was a complex system wich required you to manage the population of any conquered city as the population would be unhappy about it. In a much natural, flexible (and better) way than flipping cards an gobernors. And yes it was the first civ game, 30 years ago.
- Is too restrictive in the most boring way possible. Colonies were a thing in real world because the Civ mechanic resembles little to nothing how culture, or loyality or anything works. Managing and empire has nothing to do in Civ VI with making good policy, military, or economic decissions, or even good diplomacy or science. It is all about using the right game rules and cards to get the better game numbers.
I know mechanics are abstractions of real life concepts. But in Civ VI mechanics are not abstractions of aspects of managing a Civilization, or empire building. Mechanics in Civ VI are videogame abstractions, of a cardgame abstraction, of a board game abstraction of a concept, represented as a linear formula. And any resemblance of the original concept is buried on layers of abstraction, and tuned to be a balanced number for a multiplayer card game, instead of to provide any meaningful or fun experience in a civilization management game.
I have seen 30 years of Civ games. And as much as we have gone forward. I think in many ways this game, with all the improvements in graphics, sound, AI, accesibility, hardware, ... of 30 years of technology and experience making civ games with added and improved mechanics. Civ VI does the very basic thing is supposed to do (being a game about creating and managing your own civilization). Far worse than the very first attempt of doing it.
This is not the only mechanic and feature that is in my opinion is worse or is still missing from the original after 30 years. Starting from the intro of the creation of the earth, to the timelapse fast replay of the entire history of your game at the end. And includding things such as some diplomatic and spy options, the Palace and Space Station building views, meaningful worders, citizen management, having an AI that was able to play the game...
One thing I remember distintively, is how you could see the rise and fall of civilizations in the fast replay. Reflecting massive struggling power shiftings and wars. If we did that on a Civ game today, we would see the civilizations expanding to fill the entire map, maybe one civ fall at the beginning and then just a static world with nothing happeneing but an ocassional city flipping, or taken every couple hundred of years, most of the times just to inmediately flip back. And maybe some mixup, if the world gets flooded, as not a single civ will build barriers. You will see the world changing after early game if the human player does it or as the game forces changes on the AI civs with game rules, almost never caused by the AI, never following any identifiable plan.
Im not saying this game is worse than Civilization I. It is of course much better in all technical aspects, and some changes and additions along the years have added a lot. What Civ VI is not, however is a better game about managing a Civilization, or even a better 4X strategy game, than Civilization I.