A Landing Page MVP is about Market Testing

There is an argument for just going and building something quickly if you feel you can do it quickly and you’re willing to risk that amount of time. For me this would be something like 1–3 days, like over a long weekend. But everyone has their own level of risk tolerance around this.

Conversely, a landing page MVP is about market testing. To be precise:

your assumptions about your target audience
whether they have the need you think they have
and to a lesser extent how you can reach them
and how much effort or money it will cost you.

Datapoints around all of these buckets help inform what product increment it worth building, as opposed to relying on gut feel which can be easily biased based on not having enough info or seeing the full picture—at the moment that you are making the decision.

So if you already have a lot of insight directly from other sources, e.g. speaking with your target audience segment, then you might not need a landing page MVP. Just build your product, and set up a website with landing pages when you have it ready,