Looks like it is for young people who have dedicated time for it everyday.
Personally I would like to do anything like this with no time limit and probably no monetary prizes. I think the only value of those puzzles is to fire up rarely used neurons that hopefully are still there after another year of shipping corporate products xD. I might appreciate fresh point of view from young people and new programming languages though.
There are plenty of professionals with jobs and families making time for AOC because they enjoy it. Doing the problems at the same time as everyone else is a VERY different experience from doing them whenever you'd like.
If you don't want to make the time for it, power to you. I'd recommend most people to drop off after the first 10ish days. But don't delude yourself by ascribing this as the domain of "young people" or those without responsibilities. You're making a decision. Own it.
Imho: I worked with code that has long history for my entire career. If the goal is to look at some objective quality of solution then I do not believe in time limits. The longer I work the more things getting patches/updates/remasters and value of better code goes up and value of arriving at any kind of solution overnight goes down.
The thing about AOC is that it's really less about the code that you generate, and more about the process of solving the problem. The challenge is really what you make of it. Some people will golf it, some will go for speed, other for performance, etc.
That's why it's so different to solve the problems in "real time". There's a huge community of people solving the same problem that you can interact with and bounce ideas off of. Even just a few days after the problem is released, most of that active discussion has dried up, so you can no longer participate in that discourse.
So, again, I don't think there's anything wrong at all with what you're saying, but there are other elements to consider beyond maintainable code and pristine solutions.
I agree and I happen to think the experience of doing it later than everybody else is significantly better. If I search for “AoC 2024 day 12 hint”, I’ll get better results on Jan 12 than Dec 12.