I've been an user in Brilliant since a long time and I have experienced the changes this awesome website has gone through. One of the main reasons I joined and continued doing Brilliant is for the fun of problem solving, and trying to improve my skills. However, ever since the implementation of the news-feed system, the number of good problems posted in Brilliant has been decreasing exponentially. A few months ago Brilliant was one of the best sources for some really nice olympiad problems. I am really sorry to say this, but it isn't anymore.
Take the geometry section, for particular. The geometry section has disappointed me the most. A good geometry problem should contain some angle-chasing, finding some cyclic quadrilaterals, etc. A good geometry problem isn't something you can just bash out. What's the fun of that? The problems I receive in my feed are mostly calculation based. The approach to most of those problems are obvious, all one has to do is fill in the details and make sure the calculations don't mess up. Very few of them look interesting to me.
In general, the quality of problems shared by the Brilliant staff are deteriorating day by day. Very few of the problems posted nowadays make a good olympiad problem. My reaction to most of them is like "oh, I know how to solve this! I just have to use cosine rule on \(\triangle ABC,\) then on \(\triangle ACD\) and that will give me \(CD.\) I hope my arithmetic calculations are correct!" That's not how a good olympiad problem should be. A good olympiad problem is a problem which you don't know how to begin. People try various approaches, some of them fail, some of them give partial progress. People plug in small values to observe some patterns, then try to prove them. That is the fun of a good olympiad problem, which the 230p-300p Brilliant problems used to provide. Oh, and a good problem shouldn't contain too many tedious arithmetic calculations, which most of the problems posted in Brilliant nowadays do. What's more, I find many of the user submitted problems, even those assigned with a rating, faulty. Now I'm not blaming the staff for this, I understand that they are sincerely trying to make Brilliant a better place. I just like to point out that their efforts (atleast in my opinion) are in the wrong direction.
Here's what I suggest. The current system need not be abolished. It makes the website more community-based, and is nice. The lack of good problems is what I'm concerned about.
A few days ago I saw a set containing sorted problems for the week. Now that is a step in the right direction. Every user should have the ability to post a problem, but only a selected few appear in the weekly sets. Rejected problems are kept unrated, but people can feel free to solve them. Some of the problems might also be shortlisted for future use. The staff should also start posting new better problems, I believe, although that would be probably asking too much of them. The problems, however, should be more similar to those that would appear in a good mathematical olympiad.
Does anybody have any other comments / ideas regarding this issue?