As a fan of the books & games, I thought the first season was decent. It's an adaptation of a multi-book short story collection with an overarching narrative. Without prior knowledge of the series, I may have required multiple views to understand the timeline and events. It has a similar feel to the stories, though, and I enjoyed it.
Season 2 had a great first episode and an okay finale, but meandered in the middle episodes. The substance of many adapted stories were altered. Parts that were main story in the book felt like filler and lacked necessary plot & character development. I'll never understand why adaptations leave out parts that are important to understanding the main plot and characters, yet add meaningless fluff & soap opera drama. Some characters that don't say ten words in the books are main POV characters now.
Season 3 was awful. Before even looking at the train wreck of the content, I wonder why NF released half the season, when the second half will be aired three weeks? Why not wait and release the entire series, or release one episode each week? Anyway, regardless of the stupid release schedule, the first half of season 3 is abysmal. The main actors who brought the characters to life in season 1 don't seem to want to be there at all anymore. The script writers are no longer even trying to follow the Witcher stories, they're just off in the weeds doing their own thing. The drop in quality this season is precipitous. I'm sorry to say it, but Netflix's The Witcher is no longer worth watching.