I have played a lot of CS lately and recently decided to try competitive mode.
The first game was easy (we won 16-2), the second game bumped me up into playing with higher ranks and we comfortably won (16-9), and the third game bumped me up into playing with four double AK ranks on my team and we narrowly lost (16-14) with me being on about 1:1 K:D and middle of the scoreboard.
The first and second games were fine, but unlike the first two games, in the last we weren't winning comfortably and that brings out problems in less mature team-mates. Our top player was the very definition of 'toxic', and ironically we probably lost at least one round (and therefore the whole game) because he was distracting everyone ranting about how it wasn't his fault that he just got killed.
Overall it wasn't an enjoyable way to spend an hour.
I think the main problem is that games can last upwards of an hour and you get penalised if you leave early, so without knowing in advance who you are going to be playing with, there's a risk of locking yourself into an unenjoyable game for the next hour. If you only have time to play one competitive game every couple of days, this is far too much risk to make it a good use of time. You could alleviate this risk somewhat by having a shorter competitive mode which is first to 8 instead of first to 16 (which I think would be a lot better for older people anyway...).
So at the moment... no real desire to play more competitive.