How is it not a problem if you want to sell closed-source software? I guess you can dynamically link desktop applications (although I'm not sure how this works in Apple's Mac app store), but you can't do that with mobile apps.
I have never seen anyone statically linking Qt anywhere, even with a commercial license. The main issue is iOS, where it's basically impossible to ship anything (L)GPLv3 on the app store, but that's due to Apple's lock-in policies.
Also, JNI requires you to use DLLs/shared objects, so you definitely can use them on Android.
> I have never seen anyone statically linking Qt anywhere, even with a commercial license.
from a quick grep on my hard drive, Telegram and QBittorrent statically link against Qt on Windows ; my own software also does, on all platforms. I assume there are others.
LGPL is not about dynamic linking, and there are plenty of LGPL (and even GPL) apps in the Apple, Android, Mac and Windows app stores. Like, Chromium itself is mostly LGPL and it's never an issue for electron apps, why would it be for Qt ones
