Every game needs an easy mode in order to attract a wider audience. In modern MMORPGs, this is the damage dealer role.

You cannot have a difficulty switch in such game, therefore, there are easier options available. Precisely because this is the "easy mode role", damage dealers cannot receive the same treatment as tanks and healers. It is only normal that once you are stepping into hard content, all roles matter. You cannot have an easy mode on content designed to be hard, therefore this is the moment "real damage dealers" are separated from "easy mode players". If you make damage dealer a role equally demanding than tanking or healing, then you remove the easy mode for the various players that enjoy this style of gaming.

Do not forget that there is no requirement to get into hard content while it is hard. You can wait until the content becomes easier (through higher gear and level) and do just fine. FFXIV does a fairly good job at identifying the content designed to be hard and the content that is designed to be easier. The "wake up call" a damage dealer goes through is another necessity. Either the player will push through or give up. It is the tangible point that marks a "you must be this tall to proceed". It helps a player identify which content is suitable for its play style. If the "you must be this tall" mark is a mandatory element, which stops the player in its tracks, then it signals the player that he/she better find another game.

This has nothing to do with an "aging" community. Players had jobs and families 20 years ago just as they have now. They had young and old players then, we have young and old players now. What changed is that there are so many options and alternatives, that you need to pull every possible tricks from your hat to convince players to invest their money into your game. Competition is so fierce that you have free MMORPGs. One of the most expansive game genre to produce has free titles on the market. Worse, sometimes those free titles are able to provide a similar experience and graphics than the paid options.