I see ...
I downloaded it and I saw what the "problem" was or is ...
First, "2k" means (as far I know) 1920x1080p, your images are 2560x1440p which is called usually "1440p" ... that aside, your image quality is lossless (100% quality setting) as far as I could see, which makes those files still pretty big - above a couple MB per file mostly, even up to almost 5 MB in some cases - still way smaller than png's with the same resolution though ^^
I opened a couple of those pics with the standard "Windows Paint" and clicked on "save" ... the file size shrinked to a third or less and I mostly could not see any visible difference in quality, I say mostly because only if zoomed in (8x zoom) I could spot here and there small artifacts ... and as far as I know the standard setting for jpg quality in "Windows Paint" is only/just 80%. You can try it out for yourself and compare the quality ... almost indistinguishable I would say - even for 80%.
With a different graphic software (freeware like "XnView" or XnConvert") and quality settings set to 90% you would end up with half the file size - or even less.
Which means, half the space on your storage drive, half the time for uploading and half the time for us to download

A "casual" player (the majority) spends maximum a few seconds per pic on screen and the focus is split between the pic and the text ... there are a few quality fetishist, I know ^^ ... you see what I want to say? For an optimist the glass is half full, for an pessimist half empty, but for an engineer/developer it's twice as big as it's needs to be ...
However, you do you - this is just me trying to spread efficiency around
Thank you for creating and sharing your project with us here
