Even setting up your automated tests on multiple platforms can cost a ton of money on CI infra alone. Besides increased server costs some architectures cost a lot more to rent on cloud-CI systems (cough macOS) and setting up the local infra to run tests on-prem can be a huge endeavor and each new platform added has fixed costs.
Nevermind your cloud CI randomly dropping support for one of your archs.
Nevermind your cloud CI randomly dropping support for one of your archs.