Having all applications run on all platforms is a dream since the beginning of times, SW wise
Some people mention Java and that it is already happening, but I'd say that it isn't.
Even applications on the same platform, say Windows, can't always run on all variations of Windows, and the same goes with Linux unless you are able to do some or a lot of tweaking.
However, IF it could be made, then we would have a level playing field and the platform producers would have to improve their own platform to make it viable for users and customers.
Just like in the car industry, where roads, parking refueling locations and other infrastructure is the platform and the cars are the applications.
But it won't happen, and just like biological mutations, even if at one point it could be made, things will evolve and people will want different solutions to different situations, so it will mutate away from each other.
Like a mainframe won't easily run a mobile phone application or vice versa.
Nice dream but N/A