Generally speaking, whether someone is a subscriber or not simply depends on how invested they are in the game. Back when I was a Baron I had two characters, and eventually made two more alongside my main one to have a trio together and a single one elsewhere. I only started paying for the game after playing for 9 months in various capacities.
Most players don't need the First Ones, some do, and some others abuse it. I've never questioned my own use of First Ones since I've only ever created more when I've had a need to make more for various reasons, and mine tend to be spread out across a very large area. The only real problem I see with FOs is that some people choose to have disproportionately large numbers of the, and then issues arise.
I started the game amidst a large group of players, and we all felt comfortable with our numbers of FOs. A single character can do meaningful things, and if you're playing the game as it's designed to be played, then it's actually very fun without needing more First Ones.
Whether you think that it's done right or not, corruption is a very impactful mechanic which has large cumulative effects. It is mechanically better to have lots of players than it is to hoard stuff, and having more players tends to be more fun anyway.
With this in mind, you need to remember that First Ones are fairly useful in war. And whilst it isn't quite a straight linear improvement, having more FOs available tends to make wars a lot easier. Not all players are the same, some are more active, some are more committed, and some contribute more than others. If every player had the same number of FOs, the game would devolve into it being a race to attract as many players as you can. Having players as a currency would detract from the spirit of the game. When I started playing, I didn't need many FOs, and now I use a fair few across many locations. Player numbers becoming the defining factor of realms would not be beneficial, in my opinion. Regardless, this is a good talking point.