You can target Android with Swift/Swift UI with SKIP.tools (skip.tools) and SCADE (scade.io), both of which use native controls on Android as well.
Plenty of companies/people use it. It's open source with commercial backing. It's free for commercial use. It existed well before flutter. Uses a language people actually use (Java) as opposed to Dart.
Why would people use flutter which is constantly in danger of being spring cleaned by Google since it makes absolutely no commercial sense. Without Google's support it becomes an unsustainable over engineered brick of code.
It also came out way after PhoneGap and wasn't backed by a huge company with a huge marketing budget.