I had a DSLR camera which was very good in 2005, yet when I bought a 2012 mirrorless, I was born away. It isn't about the megapixels, the staggering difference

I had a DSLR camera which was very good in 2005, yet when I bought a 2012 mirrorless, I was born away. It isn't about the megapixels, the staggering difference is the high ISO performance. I just met someone with a new full frame mirrorless, a very expensive camera. The shooting experience use worlds apart: huge luxurious viewfinder, fast autofocus with face tracking, it's a monster. But at the end of the day, if I put in the work with my 2012 camera paired with a cheap but great manual focus Samyang 85mm f/1.4 I'll get almost the same results.