We don't force you to use PlatformIO. If you like manually manage build scripts, toolchains, etc. and understand how to do that, you can switch PlatformIO to your own build system. I remember that I already explained to you how to do that (own `build_script` entry within PIO build environment).
> There's another argument though: Usually I need only one board. Maaaaybe two.
Thanks, I've heard your feedback. PIO is intended for developers who don't want to focus on the 1 board for 1 year. We don't live in 90-th, today each month we have new boards, MCUs, connectivity solutions, etc. PIO allows you an easy switch between them. If you don't know at 100% which hardware do you need for the next 1 year, PIO is the excellent tool here. You can experiment with dozens of boards and find better hardware according to the project requirements. They cost a few $$$ today.
Stay tuned for our news. We are working on the very interesting things which will be announced soon.