My attention is valuable (at least to me and those around me), and I choose not to waste that attention on applications that are built with a framework that quite deliberately disrespects the platforms I choose while presenting a badly drawn version of the thinnest layer.
On macOS and iOS, Flutter pretends to conform to platform standards, but it does so very badly (I can always tell if I'm using a Flutter app; it's just off…and my battery life suffers because Flutter is such a bad citizen). Honestly, I probably wouldn't hate Flutter on iOS if it didn't pretend to conform to iOS standards while missing the mark (just like every Google app misses the mark on what an iOS app should look like; it's just wrong).
On the web, Flutter is even worse by pretending that there's only one HTML tag, <canvas>, and throwing away _all_ of the rest of HTML to do everything else that HTML does, but worse and less accessibly. That, ultimately, is unforgivable and a waste of everyone's time.
Regardless of how useful gioazzi's project may be, the technical choices made put it well outside of the boundaries where I am comfortable recommending its use to anyone — and that's fine. I posted a similar take about someone who did a Show HN about a project they made which required a Google login; I was interested in seeing what they had done until I saw that requirement. That technical choice, while a valid one, put it well outside of my "I will try this thing at all" zone.
I shared this stance because I know I’m not alone, and people need to know if their architectural choices put them outside of the market they are targeting. I might or might not be in their market, but it's still a useful thing to know that there's this one asshole in Toronto who won't use it because they took the "easy" way out for pseudo-cross-platform support. (I do not have the same reaction to React Native, but that's because it ultimately doesn't try to emulate the platform.)