Because trip planning is such a huge umbrella to most people?? This seems fairly obvious to me and I would hope the team keeps that in mind as well.
You're asking people on the DIS, most have been to the parks before. They aren't looking for a play by play of everything. But things like going over new products or policies (such as when FP+ was introduced, MP, and now
Genie+/LL and like I mentioned on the other thread when Disney reduced the size of allowable strollers and banned wagons), new attractions or shows, new events (including after hour stuff), park reservations (including discussion about Disney removing that restriction for date-based next year), park hopping restrictions (updates on that if that is occurring like when DL adjusted their time), dining reviews, resort reviews, transportation reviews (I remember good discussion about Minnie Vans for example when they came out), navigating the parks depending on one's traveling party, events that Disney puts on (F&W, Flower & Garden), etc all of these can be part of trip planning and of interest to people at various points.
Most people find this stuff out organically, the podcasters are mentioning this stuff and that's how people are learning (if they are tuning into a podcast to begin with).
If you asked people do you enjoy finding out new things about the parks, hearing about a new restaurant or a new menu, how is a refurbishment at a particular resort going, what are the party offerings this year and the dates, and so much more you'd probably get a different answer. You can find several threads on the DIS recently discussing how impactful construction on resorts is to some people either the view or the noise, that is absolutely part of trip planning.
And several posters are absolutely correct, it's hard to answer the question now in 2023 when the discussion shifted away from a lot of things one could consider trip planning in several years past. If you still stuck with listening to them well then yeah you wouldn't be likely consider it a main reason you're watching any longer.
So I'd consider this more like a question that is framed with an intended bias answer pool.