I think a lot of people have this weird mindset about FFXI, how much buying power your $12 has and what is possible.
Inflation means money loses value over time (not going to go into why but we are about to have a massive decrease in the value of our money soon - printers go brrr), which means a loaf of bread or jar of coffee costs more more today than it did 10 years ago. Prices and your wages increased with inflation all the time, which means this increase does not hurt you.
Go ask your granny how much bread and coffee used to cost and then look how much they cost now.
https://www.usinflationcalculator.com/
FFXI has never increase the price of it's subscription with inflation, which honestly is crazy to me. They are losing money and due to this the game is less profitable today than it was 15 years ago even if it had the same amount of players.
If the FFXI subscription fee raised with inflation (as everything else in the world does) it would cost today $16.44. This means, that in real terms you are paying 37% LESS for your subscription than you were 15 years ago and that they are getting less money from you.
So:
2004 price = $12
2021 price should be = $16.44
This means you're getting the game 37% cheaper than you used to, even though the numbers look the same. Other games offset this loss with cash shop sales, FFXI does not have the core infrastructure to support a cash shop.
To try and counter this they have added mog wardrobes to try increase how much you pay in-line with inflation, to get the same amount of money that they used to. This is however not compulsory so many do not and so just get the game 37% cheaper.
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Secondly, your $12 ($3 a week) a month doesn't even pay for 10 minutes of 1 single developers wages. The way the game makes money isn't from your $12, it's from tens to hundreds of thousands of other people paying $12 and the combined force making a lot of money to pay wages.
As such, if the game has less subscribers today than it did 10 years ago they can't have a big team on it as they used to. They can't pay their salary.
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Lastly, developers work with specific engines. Most of the developers at SquareEnix that work on other projects are proficient with and experienced with the current engines they use, they almost never work with the engine FFXI was made with. As such they can't just ask one of the programming team from another game at the company to come make changes to the core programming of FFXI as some other game can. This is why things such as the 56k cap etc can't easily be changed.
It would be like being used to working with photoshop in 2020 at your company and then your boss telling you he wants you to make a new ad to be sent to the papers, but instead of using photoshop you had to use corel draw from 2005. Are you still going to be able to create that artwork in an hour and will it still be at an acceptable quality?
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They can still add content, they can still make changes but core features of the game are far harder to change and so far more expensive and time consuming than you would think they are.
The fact the game is still getting updates is a minor miracle and a testament to the love the developers and we have for the game, they could easily go work on something else or just retire if they wanted to. One of the people that used to work for FFXI decided to move to go work on the FF7 remake 4-5 years ago for example.
This is not to say we should not ask for new things and expect the best, this is to say you have to understand the reality of the situation too.
TLDR: FFXI does not increase its sub price with inflation, so you're probably paying less and the combined income of all the players is less than it used to be.
Have realistic expectations of what is possible.