I dont think i agree with that, developers are certainly and most definitely not afraid to make a Witcher 3 game, considering we are getting 2-3 Witcher 3 clones every year. What happens however is that most of the developers failed to replicate the charm and the experience it offers, i think thats what some people call "heart and soul", the game had those simply for the reason it was made by people who cared about the game and its source material, everything feels authentic, the place and the world they crafted feels more real and authentic, perhaps because it was inspired by slav mythology and atmosphere, the right man in the right place? probably, im just speculating here.
Every quest feels worthwhile because it was handled with as much care and love as possible, the writing and how characters are made was engaging so people easily related to them, i find it fascinating that its the 3rd game in the franchise and despite most people ignoring the prequels it managed to become very successful, thats not to be underestimated, i personally couldn't allow myself to do that, so i replayed all the games to increase my chance of liking it and boy it did help, by the time i reached the 3rd game, i immediately started to appreciate the improvements lol.
Also big part of the acclaim goes back to the DLCs, the 2 expansions certainly elevated the game, without them i dont think we would still be talking about Witcher 3 as positively as we do. Although i doubt for people who hated the main game they are going to change their mind, but for people who liked the main game, these 2 expansions made sure you will like it a lot better.
Also probably because Geralt is a likable protagonist, the Witcher 3 clones had bland or uninteresting or sometimes annoying protagonist, whereas when it comes to Geralt its easier to relate and roleplay yourself in his shoes.
The game also still looks great due to its great art direction and pretty visuals and constant attention from CDPR and its community such as Next-Gen upgrades and TV shows.
Finally i want to note that despite its shortcomings, the game probably managed to stay in the talks for game of the decade because of the harmony of its structure, everything flows together, from the world to the atmosphere to the writing and even to its gameplay, its one of the games that you point out and say its more the sum of its parts rather than just one aspect that really stand out, although i would say there is aspects that stand out such as side quests and characters.
As for making another one like it, I dont think its that hard, all you need is a competent writing team and people who are passionate, thats it, the game is not complex or anything, the open world, the gameplay and the main story are not some abstract complicated five dimensional stuff, no its actually simple, and could be improved upon too, it just needs less soulless people and more passionate ones.
The success of W3 influenced games like Assaassin's Creed, Greedfall, Horizon, Ghost of Tsushima and Hogwarts Legacy. I would say out of those the one that came close was Ghost of Tsushima but still even that still has much more to reach it.
Forespoken clearly did not 'work' in the current gaming landscape so you are definitely no authority on what works.
(just piling on)
Funny because if i remember correctly rofif said he was polish, its rare to see a polish person dunking on W3, its like a gaming icon to them at this point, praising it feels like a national service