Why the quality of tasks in recent contest is getting worse?

Before, codeforces tasks often requires data structures and algorithms like graphs, binary search, and techniques like dp and d&c, but in recent contests (not all, but most), most of the tasks don't require them. Those tasks only requires observations to solve. For example in Codeforces Global Round 29 (Div. 1 + Div. 2) qA-D, I can't see any dp, any graphs, any data structures, but only stupid observations and greedy is needed. I dislike this style very much.

First of all, usually the observations are not easy to prove, therefore most contestants are solving them by pure guessing. This is basically “if u can guess it correctly, you can solve the task or else you will waste 3 hours to debug a wrong solution”. This is requiring more luck than real skills to get good results.

Second, this is making hard work useless. Before, people can improve their codeforces performances by learning more algorithms or techniques and practising. Now, practising is a lot less important as the only skill required for getting good results is observing and guessing patterns.

Actually, not only codeforces contest have this issue, but even in IOI style contests (for example APIO2025 which have two interactive and one greedy with strange observetion, and IOI2025 day 1 which have 3 non-batch tasks), data structures and algorithms is becoming more and more rare.

I am not writing this because I'm angry for my large rating drop, but I really think this style is making lots of negative impact on competetive programming.

I sincerely hope OI contests can be great like before.

Upd : many of the comments are saying codeforces contests are good for their observation based style. I DO NOT think it is wrong, but i think it would be bad if the task requires ONLY observations but not data structures and algorithms. A task is also bad when it only requires dsa knowledge . A true good task should require BOTH of these skills and they are BALANCED.