This is a good reason, because at the end of the day, you have to enjoy ot if you put that much work into something like webcomic.
If you don't enjoy making it in mobile version, then it's best not to.
You can always downsize print res 300 dpi to 72 dpi mobile version later if you ever want to
but you cant upsize from mobile 1000px wide 72 dpi to a nice 300 dpi printable version
so starting with print format is best if you think about it, since conversion can always be done anytime later
the beauty of the internet is that things doesn't go out of stock in the shelf,
once you put it up there, it still can be found years later
I think for a fan of desktop reading, mobile is not something that will replace desktop/laptop reading
All it does is reaching new potential reader who download app like tapastic/webtoon/lezhin etc on their mobile phone
But I gotta admit, your engagement ratio will be higher with those who read it on something that has a real keyboard, than virtual ones on tiny phone 