I’m going to assume based on your comments that you’ve never ported an application from 32 bit to 64 bit, but it is not as easy as just flipping a compile time switch or changing the value of a type. Or if you will, code that compiles and code that runs and does what you expect it to do are not the same thing.
Running 32 bit software on a 64 bit OS requires that all of the libraries that the application requires be installed as 32 bit as well, making getting it working on some operating systems more involved than others. However that would require such a version to exist, which would require SublimeHQ to maintain and support multiple versions.
Being 64 bit allows, amongst other things, access to a larger memory space which is for example required for the git support in ST to work. This is why even when there was a 32 bit version available, the git integration was still not available.
If you require a 32 bit version, they exist, you just can’t use the latest versions (though in fact I believe there are unofficial 32 bit versions of ST4 if you know where to look, which are entirely unsupported so if you have issues that’s unfortunate).
At the end of the day, using recent things requires recent things, and sometimes that’s just not possible. I would love for example to use a fast charger to charge my car to save on gas costs, but since my car isn’t electric that’s not in the cards.

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