Thanks for this list. I find all of them are missing features that I would want for diagrams I hand made recently. Of the ones on this list only one seems to handle diagonals ( https://textik.com/ ) and that doesn't have a fill function AFAIK
I created the box and triangle in textik.com but I had to manually edit a bunch of corners and manually fill it in.
I'm not sure I'd pay for Monodraw. Even though it's only $10 is a native app and Mac only. I do so much on the web and use so many machines and draw diagrams only a few times a year that I think I'd prefer something web based or a VSCode plugin.
[1]: https://xosh.org/text-to-diagram/