Software development technology is getting close. A couple few more years maybe and that problem will start to go away fairly rapidly [relatively speaking], like possible 30-40% cross platform by the end of maybe 5 years-ish. 12 year android dev here seeing the light at the end of the tunnel with some newer performant (dev wise and user wise) frameworks and architectural patterns. Of course this all depends on Apple not saying FU to the entire industry in a dramatic, squashing those frameworks with their iron fist sorta way.
Something along the lines barring the compilation of iOS apps with 3rd party tools or some such in TOS or blocking apps made with them from the App Store outright. Not saying the would, but if they had reason to fear they are losing control of something in their ecosystem, no telling what they would do. Just would not give a zero chance of something crazy as such happening.