In fact, brute forcing mnemonics is the slowest way to get to your coins.
It's way faster to target the address directly, but even then you don't stand a chance and have to rely on pure luck.
The only thing left will depend on how you reinstalled the new operating system and what you did with it afterwards.
If you did a slow format everything will be gone, but if you did a fast format everything that was not overwritten will still be there.
Then how this guy did it then if it's impossible?
https://medium.com/@johncantrell97/how-i-checked-over-1-trillion-mnemonics-in-30-hours-to-win-a-bitcoin-635fe051a752
Maybe you should read the article this was not about 12 unknown words.
Luckily, we do not need to actually check all 2¹²⁸ possibilities because Alistair was going to release 1 seed word every couple of days.
Each seed word we collect reduces the possibilities we need to check by a factor of 2¹¹ or 2048.