Fornite is only at the top. League of Legends brings in billions in revene per year too. Valorant, Apex, PUBG, Warzone, CS:GO DOTA2, TF2 who have generated at least hunderds of millions per year in revenue and have idividually since release each generated multiple billions of dollars in lifetime revenue. We haven't even started taling about the games have millions of paid monthly subscribers like World of Warcraft and Final fatasy or Asian F2P games. Multiplayer is where the money is at.
For it to be cinematic, all they need is scripted events and cutscenes integrated which we've seen in games like Destiny, MMOs, The Divsion and other games. That's all there is to single palyer games when people call it cinematic.
Witcher 3 is more a lighting in a bottle becaus most single palyer games dont' get that kind of sales numbers or that knd of community on the developers dicks. There were poitns where Witcher 3 posts on REddit and twitter would trend daily about how great the game and how not evil the company is. And again even wtih those sales number the revenue/profits aren't that great. Looking at CDPR's revenue for the entire company itself since 2015 we're looking at around ~$1.278B but that includes GOG, old witcher sales, Gwent, Thronbreaker and Cyberpunk 2047 (13.7M copies in 2020) across 5 years. So again even with all that the Witcher 3 lifetime revenue is not that great especially over such a long period of time.
Going single player isn't a smarter target it's a safer one. With safer low risk = low reward.