See what PetaPixel says about the failure of Pentax in the mirrorless market, despite the efforts paid in the past two decades.
By the way, for what PP has listed out for the 37 interchangeable lens digital cameras wich Pentax has ever produced, I have bought more than one-third of all the models as follows:
From 2003 to 2021: My Pentax APS-C bodies acquired: *ist D/DS/DL2, K-100D, K-m, K-x, K-r, K-5, KP and K-3III, total 10 out of the 29 models produced.
From 2011 to 2014: I bought the original Q and the Q7, hence 2 out of 4.
From 2016 to 2021: I got the K-1, but I don't think Pentax has really produced 2 full-frame bodies as the K-1 II actually is just a mild variant of the original K-1.
From 2010 to 2014: I purchased the 645D, 1 out of 2 for the medium format bodies.
So, I acquired a total of 14 Pentax models out of the 37 that they have produced.
Besides what PP has mentioned about the causes the failure, which I generally agree with, I think from the user's perspective and practical point of view, the K-01 and the Q series failed in two major ways, which are the lack of EVF and fast Wi-Fi support. I consider that these are basic essential features nowadays, especially for mirrorless cameras and for easy social media sharing on-the-go. All in all, the external LCD monitor is really rather difficult to view under bright light environment outdoor. Without an EVF, it is indifferent to shoot blindly and composition and shooting have become rather difficult with such handicapped mirrorless cameras.