[Peter5]

2.5 MB is for most of the Lazarus Component Library (LCL) with minimal size increases even as program complexity grows. For example, Dadroit JSON Viewer EXE is less than 6 MB while having complicated tree views, JSON handling, networking, and more. By the way, an empty CLI EXE on Windows is less than 50KB.

[klipt]

Why doesn't the linker strip out unused code?

[magicalhippo]

I imagine it's for the same reason Delphi can't strip much, which is that it supports run-time reflection. You can create an instance of a class using a string of the name.

Forms (windows) are deserialized during loading, which relies on this mechanism.