VCL on Delphi and LCL on Lazarus ( https://www.lazarus-ide.org https://www.lazarus-ide.org ) are pretty neat and feature rich wrappers. It's not the rendering

VCL on Delphi and LCL on Lazarus ( https://www.lazarus-ide.org https://www.lazarus-ide.org ) are pretty neat and feature rich wrappers. It's not the rendering that's the issue - it's the work involved in making them conformant to the different OS guidelines, and dealing with the intricacies and quirks of each OS. It's more practical to extend and enhance what is lacking, rather than rebuild the whole thing again in 4 (Windows, macOS, Linux, FreeBSD) different ways.