Sorry for my poor English.
I am talking only from Div2 perspective as I think Div1 contest are still ok from this point of view.
During 2020 codeforces moved from having problems with variation over known algorithms and data structures to constructive heavy contests. I am not saying that having constructive problems are bad but their amount is way too high and I guess most of us will agree that now a days problems on topics like binary search, DP, Graphs or segment tree or other data structures etc are almost extinct in Div2 rounds.
Lets take last Div2 Codeforces Round #696 (Div. 2) as an example someone who knows programming language and basic number theory could solve problems till E and can get 1st rank. So in theory someone could become a master or International Master with just number theory and programming language knowledge.
I used to like constructive problems a lot (Actually one of my stronger topics) but now a days there are just so much constructive problems that they are just more or less becoming boring in my personal opinion.
I would like to present my points why this is wrong
- Sometimes many problems are just checking too much cases or having just one observation. It just makes the contest that who can observe something quickly other than visualising the problems from different angels and brainstorming.
- Variety of problems in a contest are decreasing
- Contests are lacking a main thing that you can learn new topics by upsolving problems and reading editorials as now most of them are based on few observations which are less likely to repeat or generalised. Now you can learn new topics only through Div1 contests or through only last few problems of Div2.
- People reach div1 without having too much experience of basic data structures and algorithms and then have to solve problems that require good experience over those topics and in turn creates knowledge gap.
I would like to ask contest admins to also look a contest from a perspective that is it teaching some new topics to someone who is just starting and also people to practice common topics to get a stronger grasp on them. Having too much constructive problems neglects this aspect of contest.