First of all, I don't think many games have enough dialogue to deliver fresh lines each day of the year for 8 different personalities. It's also worse when a game is repetitive like Animal Crossing,
Second, I highly disagree with statements like "islanders are robots/not alive/lobotomized". Just because of the simple reason that I don't find them to be that, I feel they are full of life because even if they don't deliver Shakespearean dialogue every hour, I can see them playing, singing, eating, etc. Of course I know that many people like to dismiss all those activities as "social media bait" as if that's a big brain take, but I don't. But that's highly subjective, and until we are able to compare the dialogue dump of all games side by side (which is almost impossible) we're only left with some facts: parts of NH dialogue is unfortunately behind some contextual dialogue, NH dialogue doesn't feature tutorial dialogue like its predecessors, NH "ping" seems to be lower than other entries, etc.
And finally, I just take 2 minutes of my time to speed through the contextual dialogue, which is the lines you mention. Just today, while decorating the island, I talked with four islanders. Zucker told me the lazy contextual (meeting me on my dreams), clothes contextual (he told me he looked great on his denim jacket) and then I got a line about running like an airplane and then taking a nap which I think I have seen like 2 or 3 times on 500 hours (I won't say it's new new but I didn't remember it). Bianca gave me peppy contextual and then she told me C.J. was my visitor, which I didn't know so it was helpful. I then participated on a conversation between Julia and Renée where the latter told us about how she used to zap everyone with static electricity. I'm gonna play later, but for example, just today, I only got 2 "boring" and contextual dialogue, so I'm not bothered.
tl;dr: it takes me so little time to skip contextual dialogue that I don't have a problem. I keep discovering new lines every week or so and thanks to the events, some days/weeks have tons of new dialogue (which obviously only last this year, but I'll probably forget a lot of them for next year haha)