Characters.
I've always felt that the DA series has trumped the Witcher series in this regard. The companions and the romances in the DA series have significantly more depth than those found in the Witcher, Witcher 2, and Witcher 3.
That isn't to say that the Witcher series has horrible characters. In particular, Iorveth and Roche in the Witcher 2 were both fantastic, with great background stories and some fantastic interactions with Geralt. Of course, fast-forward to the W3 and Iorveth gets about 1-2 mentions (with a grand total of zero appearances), and Roche barely gets any screen time (outside of yelling his love for Temeria and how crazy Radovid is). Its also hard to overlook the one-note characters such as Zoltan and Dandelion, who had little to no growth throughout the entirety of the series.
Furthermore, I felt CDPR did an absolutely horrible job with the portrayal of Triss Merrigold. She sort of just latches on to you in the first game, and appears to be all lovey-dovey and obsessed with Geralt for no reason (obviously there are reasons, but those are mostly found within the book series, not the game). The second game didn't improve on this much, especially considering she was only around for about 1/4 of the game. She has sex with you, sticks around in the bar, has sex with you again, and then gets kidnapped. Zero character development. To be fair, though, Triss in the third game felt much more 'alive' to me, and her personal struggles were told in a captivating way (although she contributes little to the end-game, something which a lot of Trissmancers were clearly upset about on the CDPR forums).