It's a little bit my thoughts...
A serie inspired by TW3 who would follow the exact same story than in the game (like searching Yenefer at White Orchad with Vesemir, kill a royal griffon for Nilfgaard captain, meet Yenefer, going to talk to Emhyr, meet the Bloody Baron, find his wife, find his daughter and the same until the end...
Should be damn boring to watch, in my opinion (except for those who didn't play the game indeed)
Honestly, better to watch that instead of a serie
But it's just my opinion.