I don't know what they were thinking with the independent powers in VII. They're such a downgrade over what we had in VI. Everyone already knows how poorly independent powers (henceforth IP) compares to city-states (CS), but it should be pointed out that IPs are also a replacement for barbarians. A terrible one, that is.
Say what you will about barbarians - I've certainly cursed their existence plenty of times - but they did represent a recurring and unpredictable military challenge that took skill and preparation to deal with. You didn't know when and where a barbarian camp would turn up, or what kind. They played a very important role in making sure that you had at least some military gameplay even in games where you never went to war with anybody. They ensured that unoccupied mini-continents weren't just trivial to claim halfway through the game. They made it dangerous to leave terrain unattended near your borders later in the game. They made it dangerous to send a lone civilian out into the wilds, necessitating the maintenance of spare military units. They ensured that even isolated civs couldn't just blindly sim-city from the beginning of the game with no regard at all for their own safety. As annoying and RNG-driven as they were, barbarians were crucial to the core gameplay, and as anyone who has tried to turn them off in VI can probably attest to, the game felt super empty and dull without them.
In VII, barbarians were removed altogether and the effect is pretty much the same as turning them off in VI. IPs are not a replacement for them. An IP is just a CS that you might start out at war with, same as if you randomly declared war on a CS in VI. They don't emerge unexpectedly anywhere, they're always in fixed locations and cannot be a meaningful threat to anyone who isn't settled right next to them. They can, by definition, not surprise you (except maybe in the first 10ish turns of the game). They do not represent a recurring, unpredictable military threat that has to be accounted for throughout the game. It's also trivial to kill them - barely harder than a barbarian camp - or to claim suzerainship of, so by the time it's no longer the very early stages of the game, you've done one or the other and never have to think about them again. There's only a handful of them, with at most two or three that are close enough to your lands to be relevant even if they are aggressive. Compared to barbarians, they're so insignificant and easy to handle that they don't serve the intended purpose at all, and the end result is that for all intents and purposes, VII is like playing VI with barbarians turned off, and all the bland emptiness and earlygame inactivity that comes with it. And you have no choice in the matter.
And when we then dig into the ways IPs pale in comparison to VI's interesting and unique city-states, and the methods of interaction being so barebones, it's kind of an insult for the newest iteration of this series to deliver such a massive downgrade to one of the most fundamental aspects of core gameplay. Why remove the uniqueness and make all IPs of a given type identical? Why remove quests? Why remove the dynamic, interactive nature of envoys? Why make it so that once someone is suzerainship, nothing whatsoever can be done about it? The only way in which IPs aren't vastly inferior to what they replaced is in the theoretical gameplay venue of building them up and supplying them with upgrades; but in reality, this turns out to be largely pointless and not worth doing, because you get less out of it than you put in and there's really no reason to ever do it.
There's a lot of ways in which it's difficult to pinpoint exactly what the problem with VII is, but in this particular case, it's extremely obvious how severely they failed to make this part of the game good, and how easily it could have been far better, because they already had the right ideas in the past and then simply abandoned them for no apparent reason. It's just dumbed-down, seemingly for the sake of making the game less complex. In a series that is all about complexity, decisionmaking and intractivity, this is inexcusable. For an established developer with so much experience in the genre to deliver something this much worse than what they've already proven capable of in the past is just not acceptable. And it's worse in such an obvious, undeniable way that one must conclude that they knowingly, intentionally made it worse, presumably to cater to f***ing mobile phones and other such platforms that require primitive game design.