Gtk4 has a lot of potential to be disruptive if the tooling becomes at least competitive to what other frameworks have (qt, flutter,etc). For now it's a serious choice (or the only choice) if you develop for linux.There are cases where this is desirable and if you have a product that has multiple 'native' versions and that's good, but most often than not that's not the case. -Language bindings(this is where gtk is overlooked and has a solid position, being written in a low-level language it already satisfies one segment of developers and through bindings the other half)
And either:
-A decent designer tool (glade and cambalanche exist - they're better than nothing, sadly would say they're not production-ready)
-Or some (possibly community-driven, which can be the case since gtk is open) extensions for couple major IDEs/editors: think emacs,vscode,intellij-based.This is where gtk is way behind flutter/qt and i think they can gain the most since a lot of developers rely (for good or worse) on editor extensions.
And i'm willing to guarantee that gtk will be often be picked as a solid alternative.Again, this is not bashing against gtk4, because it's free and my talk is worth nothing compared to contributors, but these are just my 2 cents.