Strange - I bought a 486DX50 system in 1995 with VLB graphics and IDE cards. Ran at system bus speed of 50MHz, with no clock multiplying. That's above 33MHz!
I upgraded the motherboard and CPU after two years of problem-free computing to an AMD 486DX4-120 running at 3x the 40MHz VESA bus speed, with the same two cards. That's still above 33MHz.
That system is still my only PC and dual-boots Linux 2.4 and Win95, both of which run without problems. That's not "not working at all".
I still wish I'd bought PCI, though. It was not quite mature enough when I had to make the decision...