Actually the -main- story in DAI is far, and I mean FAR better than W3's imo. This being said 90% of W3's side quest beat the pants of DAI's side quests.
The lore, the secondary characters, the chilling trip in the future with the alternate events and consequences depending on your choices. Brilliant.
The only thing in W3's main arc that came even close was the trip across dimensions. But it ended up being a mere side show (far too short imo), and its main vilain as well, ending being no better than the sadly under developped and underpowered Corypheus.
If the whole main story had been anywhere near the Bloody Baron side quest line (alongside the Crones), Wild at Heart or the Skellige succession Quest line, we wouldn't even be here arguing and W3 would indeed (save maybe for glitches and CDPR usual jank) be one of the all time greats next to Baldur's Gate 2, Kotor, Lands of Lore, Morrowind and a few others.
Unfortunately, for me and as far as the main quest goes it fell short (very).