"Most high-quality loudspeakers are 4-Ohms"
Its a reasonable question though I'm not sure how much value an answer provides.
Saying neither 4 8 or 16 is objectively better may be true but does not answer the question. That only indicates that 4 ohm speakers can be high quality, not whether most quality speakers are 4 ohms.
Not sure why some are put off by the discussion? I am finding it informative even though I am doubtful a conclusive answer to the question will result.