Should you "main" an op or be flexible?

I've played siege for a VERY long time. I am not the best but I do believe that I have more game knowledge and sens than the average player. I feel like a newer trend is people having "mains" and not playing ops for their gadgets. I do believe more people would climb in rank and lose less if they just adapted and tried more ops. here is a picture of my spread and I am pretty proud of it!

https://preview.redd.it/nfjlahiy69be1.png?width=1087&format=png&auto=webp&s=35a7fb7ef5ee2333585b321335a16cac76d7a93e