Excuse me, but... What are you talking about?
I browsed the web with a 486 DX2-66 for many years, it took a while to load an 80KB HTML page straight off my hard drive - specifically, it was a mIRC scripting guide which had no images.
You would also have to wait a while for a JPEG to decode and display. If you were crazy enough to load one of these newfangled 4000x3000 photos kids have these days, your PC would start swapping and become unusable!
But, you need to keep in mind that the early web was entirely made up of text with the odd 16-color GIF for decoration. There was usually no flash or video, and a 24-bit JPEG of a pretty girl in sufficiently high resolution was more like a download than an embedded component of a web page! After all, a mere 50KB file takes 20 seconds to load at 2.5KB/s!
Graphics cards used an ISA slot and had 1 meg of memory! What they did at the time with that memory was store the frame buffer and enable you to display high (SVGA) resolutions!
I do have vague memories of seeing an MPEG-2 accelerator card, maybe it did JPEG, I dunno, but seriously, a web accelerator? When 3D cards finally came along (and you had to have them separately from your 2D card at the time) what they added was highly 3D-specific stuff like mip-mapping and Z-Buffer... not Flash.