There were much better alternatives, from a technical perspective, at a similar low price point, like Z80, M68000, CPM, AmigaOS, etc.
The IBM PC came out in 1981, when the dominant personal computers were the Apple II+, the Atari, and the TRS-80. The 8088 actually was a significant improvement over the 6502 or the Z80-with-bank-switching. IBM wanted to go with CP/M but Kildall blew the negotiations and ended up with MS-DOS. For all its faults, MS-DOS was still a better disk operating system than Apple DOS.
The 68000 looks nice, but AmigaOS and MacOS had a tough time dealing with its large flat address space without an MMU. And its architecture wasn't future proof anyway.
IBM tried to design an Apple II replacement shortly after the Apple II came out, and they succeeded spectacularly at that; the rest is just the burden of backwards compatibility. Apple blew it when they threw their Apple IIgs line into the trash and started over, largely because of Steve Jobs and his office politics.
We probably should start over at some point soon, not so much because of the x86 instruction set, but because the architecture of modern PCs is convoluted, hard to support, and insecure due to layers and layers of backwards compatibility.