:)
You are not alone.
(1) There are people who have cracked Prelims, but never done PYQs.
(2) There are also people who have cracked Prelims, but never done a Test Series.
The problem happens when someone reads this on the Internet and decides not to do (1) PYQs - because there is a topper who says so and decides not to do (2) Test Series because he heard a topper say so.
Then he does neither this nor that. Then he comes and blames the Internet and the topper :P
There are people who have not done Answer Writing Practice and directly write in the exam. Or not do a single mock Interview and directly go for UPSC Interview. Thats okay.
People have different philosophies.
Whatever works for you :)
People sometimes do these things at the beginning itself or sometimes when they hit a plateau.
We recommend that you do it in the beginning itself because the first few attempts are formative - sort of foundational. After that it is very difficult for them to improve, in case they do not get what they want.
Yes,you are right. We should see what works for us.
By the way: I am one of the girl/guy who has'nt written even a single mock test or seen even pyq and still managed to clear prelims both times in 2019 and 2020.
Moreover,have'nt written a single answer for mains and not even a single essay in 3 years of prep.
And planning not to attend even a single mock interview.
I still believe this exam can be cleared with 100% self study.But coachings won't accept it as it will close their shop.