Yeah, I need cross platform, and GTK looks quite foreign on Windows/macOS IMO. I toyed with custom themes, but couldn't find any I liked for a cross platform look (wanted something closer to Fluent UI).

Not just because of its looks to be fair. Not being native Rust is a pain, and GTK only really works nicely on Linux. At least without a ton of effort to fix everything (I think some apps like maybe Mypaint have done that, but I don't want to).