Yes, the fastest 486 systems could just barely do full-quality 44.1/16 MP3 decoding (DX4/100, etc) Even then a DOS player was a better bet than Winamp.
As a comparison a basic home theatre pc these days with ryzen 1500x cpu, and GeForce 1030 fanless with GPU accelerated hevc in the video drivers, can decode up to about 350Mbps bitrate of HEVC 2160p 60fps using the latest VLC build. Beyond that it starts dropping frames.
edit: tests run using sample videos from here, if anyone wants to see what bitrate of 4K they can play back before it starts losing frames.
A SE/30 would be absolutely screwed.