You shouldn’t be proud because you found a wrong way to solve a nice problem!
I agree with you completely that difficulty level of some tasks can be degraded.
I also think that lunchtime has small subtasks which are really cakewalk most of the times which makes it a good learning point for beginners. Though it is slightly disappointing for one to not get even one problem accepted. But one will learn a lot by this format and slowly this problem of not getting even one accepted will go away.
Scaling down difficulty level is an important idea and this is why I think codechef introduced subtasks in even long contests.
I would say that though these advance ideas/ algorithms seem complicated, they are actually not that complicated and can be understood by High school students specially people who are preparing for IOI. Many of the big coders learn them mostly in high school.
Personal Experience
Regarding advance algorithms, I feel same as you. I had learned them at my university. I learned C language in my first year at college. I got started with serious algorithmic programming at the end of 2nd year. The advanced topics some of them I have learned in 4th year or so. Still there are a lot of competitive programming algorithm which I don’t know. Also I did not train for IOI as I did not know about it all. I wrote my first dfs program in the summers of 2nd year.
Thank you for sharing your experience 