If you can't design with HTML and JS something you can do in Lazarus is not my problem. I can and I do it well, and in no time thanks to open source.
I mean, you're the primary author of BGRAControls. Surely you realize that there's all kinds of things you've done there that you couldn't even dream of doing in JS with any kind of reasonable performance?
Well. I was amazed of discovering the opposite.
Or I'm sure I'm coding wrong. But I compared a full screen material design button ( I know it's a non sense, but a way to check performance). The one made with CSS runs faster than mine. And also it only requires a few lines to make one.
I'm not a master in opengl like you. So you can know more in that field. But for regular controls the easy way of making them is really good with CSS and they run fast.
About animation: the "infinity turtle graphics" I made with BGRABitmap and then ported to JS. Runs faster in JS. So, it must be faster with Lazarus I understand that. But that is always faster is not true with my tests.