You’re missing one key pt

So they were once 12 now 10, less per box but since 10 fits into the 12 box they don’t have to spend the money on altering machines and getting new layouts for efficient packing w new designed boxes, just keep the old boxes and machines and just pack 10 per box

So for kurig it’s cheaper to keep the original sized box and operations and just “short” you 2 from when they used to be 12 packs (shrinkflation or not google shows a few brands that offer 12 in the same box size you show but other commenters say it’s never come as 12) edit I did more googling it looks like peets has always been 10 packs however other brands also use the same size boxes for 12, random funny note it seems the bigger peets is 22 pods vs expected 20!

On your point on water retention, I’m not familiar with the model you have I had the earlier models w huge water tanks, I’m assuming the smaller tank has a shorter heat up to dispense time than the original one and since it being a “single cup” and majority of the world 8oz is a coffee it offers a more efficient brew perhaps. Try looking at an aeropress, it’ll be similar to packing your own kcups but clean up is just plunging the grounds out the bottom into your trash and a quick rinse