No shade on the writers, the problems were very cool and clever. These kind of ad-hoc, constructive problems help with developing quick thinking and problem solving skills. And they are great in a contest as long as there's diversification in the problems. Or atleast 2 out of 5 contests focus on DSA skills too.

Majority of participants are here to improve their DS&A skills (by majority I mean people who don't have high ratings and aren't seasoned programmers). I would love to solve some questions on tree algorithms, dp, binary search, dsu or any basic/advanced algorithm once in a while to develop those skills too. I understand this might not be the priority for some participants, but this would help us keep in touch with actual data structures and algorithms.

Here is a blog (Changes in Codeforces problem style over 2020) where this issue is very well put.

PS — Using an alternate ID. Please read before downvoting. Thanks