That's because CSS layout was designed by people who thought "float" and "clear" were a good idea, tables were bad, and, when in doubt, make it Turing-complete and dump the problem on someone else.
2D and 3D tools get this right. CAD programs, game engines, and animation programs are all far better at positioning things. They have far better layout engines and constraint systems. This is really a constraint problem. Autodesk Inventor and Fusion 360 have good 2D constraint solvers, ones that can put something on a centerline, or parallel, or whatever, including curve tools. Webland never got that far.
2D and 3D tools get this right. CAD programs, game engines, and animation programs are all far better at positioning things. They have far better layout engines and constraint systems. This is really a constraint problem. Autodesk Inventor and Fusion 360 have good 2D constraint solvers, ones that can put something on a centerline, or parallel, or whatever, including curve tools. Webland never got that far.