Exactly. Setting up your GNU based embedded toolchains and make-files from scratch is something that hackers/hobbyists do.
In production, where you have deadlines to build firmware that is set to ship on millions of units, and your company's future is on the line, you just buy how many Windows Keil/IAR licenses you need, and get on with your work, regardless of how you feel about proprietary software.
Remembering the lengths a former employer would go to fit code into the 32kB limit of a free dev tool because they didn't want to shell out for the unlimited paid version.
No offense, but that sounds like a poorly funded company.
We had the opposite experience, we paid for IAR since that was the only compiler to generate binary compact enough to fit in the 256KB version of the chip and not have us spend extra to upgrade to the more expensive 512KB SKU.
If you're laughing at this, do note that at scale, costs add up significantly even if we're talking about $.50 and a license to a good compiler and debugger can have an amazing return on investment.
>the toolchain used for building is some customized thing. I work in automotive.
That's because in automotive the microcontrollers are more complex, with multiple cores of different types doing different things, so the build process is more complex therefore the final binary goes through several steps like patching various calibration data, FPGA bit-streams, cyptopgraphic keys, fuses, debug data, etc. but even so, those custom toolchains still call a comercial compiler via command line using some perl/python scrips at the end of the day.
You can script same steps with IAR or Keil if you wish, their compiler support the same command line functionality, except that in IoT we mostly used their solution 'as-is' since it worked well with their debuggers out of the box meaning quicker time to market.
Automotive development has a lot more crust in general due to legacy, safety, legal, plus bs stuff like the entire Autosar stack needing to be added to each build whether you need it all or not so a lot of inefficiencies build up over time due to this inertia leading to some insanely complex and lengthy build processes.
In production, where you have deadlines to build firmware that is set to ship on millions of units, and your company's future is on the line, you just buy how many Windows Keil/IAR licenses you need, and get on with your work, regardless of how you feel about proprietary software.