i think duel decks are a no-brainer for many reasons:
champion decks get put together and released, and then aren’t legal anymore by the time they release due to MWL
champion decks are usually pretty complex, needing a much higher understanding of the game to pilot (this isn’t necessarily a bad thing, but for a true beginner, it can be very daunting)
they aren’t necessarily balanced with each other
duel decks solve so many of these problems. players get an introduction to a faction’s colour pie and has a matchup that is (hopefully) balanced and fun. they’ll likely be legal for longer since they won’t necessarily have really overpowered cards. the complexity can be tailored.
with the cardlist (and potential modified rules), veteran players can keep a set on hand for introducing new players to the game.
also RE: the completion packs for the core sets. i think FFG has gotten away with incomplete cores for so long that they don’t think they need to have these
’you only need to buy extra cores if you’re competitive’
even the most casual person will still want 3 Hostile Takeovers, for example; hell, i wanted 3 toolboxes when i got into the game. i think the argument that ‘you only need 3 copies of the core if you plan to go to tournaments’ is a a huge copout, especially considering the lower attendance lately
but i’m not in on the FFG marketing team and don’t know the kinds of research they’ve done. i don’t know the actual production costs or logistics, but all i see is we’re getting champion decks but not introduction decks, we’re getting more and more expensive OP kits, lower numbers for weeklies and tournaments, and TD was apparently some great casual event that was actually really fun, but overall the experience was very rushed, unfulfilling, and are they actually planning to do more casual support?