As someone who was doing frontend development since before CSS existed (I jumped in somewhere around when the <center> tag was introduced), I can probably answe

As someone who was doing frontend development since before CSS existed (I jumped in somewhere around when the <center> tag was introduced), I can probably answer any of your questions. Most answers—especially for those early features—boil down to folks from the desktop publishing world wanting features they've always had, using terminology few programmers had ever heard, and looking to use layouts everyone in their community was already intimately familiar with. Some things got lost in translation, but a lot is just an artifact of desktop publishing not having the same goals or desire for algorithmic elegance that developers were used to. Then of course were the tradeoffs. Remember that when CSS was first introduced in Internet Explorer, 16-32MB of RAM was typical if not advanced. The user had a 512MB hard drive on a good day. There were no GPUs as we think of them today. There were some 2D accelerators (good ole Diamond video cards) that took ridiculously slow rendering up to the level of very slow rendering. 800x600 target resolution was typical for web development. No one really knew what they were doing, but everyone had an opinion, and a lot of those opinions were incompatible with one another. A lot of temporary stopgaps were put in just to solve the problem of the day only to end up part of our technical debt today. ActiveX and Flash (and <applet>) solved real problems, but were never architected as a cohesive part of the whole. SVG took way too long and progress was crushed under the weight of committee. XML touched everything and was universally agreed upon as the glue moving forward… until it wasn't. We still call them XHR calls even though they rarely fetch XML resources anymore. And layout is hard. Damn hard. Ridiculously hard to get right, and that's when you have a well-thought out plan and universal agreement. Which Microsoft and Netscape most certainly did not have. Neither really had a solid reference point. Correct behavior mostly boiled down to "how it renders in that browser version right now". We really have come a long way. One should expect warts and scars. All things told, I'm really happy with how modern CSS turned out. It may be complex, but so are the outputs it is meant to produce. Those who pine for something substantially simpler I believe have a diminished understanding of the problem space.