No, that's /wrong/. The 68K was a predecessor
No, that is /right/. Whatever it was - it was! In past. Today those 68K which survived are lo-power lo-perf microcontrollers.
Same way ARM used to be super-top attempt at super-computing. Was. Then it became lo-power phone processors. Now it seems ot going back to performance competitions.
Same way Itanium once was, for awhile, outperforming x86. Does it make VLIW suitable for general purpose computing? No. Itanium lost the race and was moved to ever shrinking niche.
IF (which i doubt) there really were hardware limitations that made 68K benegitting from LSGA bytes order, then those probaby were the limitations that helped it loose the race to other CPU lines.
AFAIR the PowerPC arch also had endianess selectable. Did it help PowerPC overpower Pentiums - in long run! - or they lost the race and make Apple escape to x64?
The observable experience shows that reversed endianess does not help performance and maybe harms it (like, indirectly, speding CPU developera manhours on developing workaround to compensate for endianess. But this is sheer speculation).
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BTW, from Thinking Computers ( which are looking great i admit, a real show of force in elegant design, i remmeber i used to oogle those photos before), i came to this:
https://en.wikipedia.org/wiki/MasPar The DEC researchers enhanced the architecture by: .... making the processor elements to be 4-bit instead of 1-bit
Sounds like a doom was spelled on pure bit-slicers. Whatever elegance they had in abstract math, the real world disagreed and insisted on multi-bit fixed data frames being read/written. Which given some decades, made 64 bit a a minimal RAM data exchange frame. Which invalidated the whole "compare only first byte - save on bandwidth" argument.
And personally, i have my sweet spot too, i belive balanced ternary computers were the most elegant. But... i would not argue we must try to resurrect them in general and replace actual architectures with them. Sad, but... case long closed.