If you equate proficiency with the ability to point spar, then I suppose one must spar to achieve proficiency in that.
On the other hand, not everyone who trains wants to spar. I don't spar because I have heart disease. Would you suppose I'm unable to defend myself?
I'm glad you noted a difference between karate proficiency and sparring, especially tournament point sparring. They are two completely different things.
Prior to 1930 there was no sport karate and basically no sparring as we now know it. Does this mean that the Ryuuku (Okinawa) king's bodyguards like Matsumura, or Miyagi, Motobu and Matsumora (who took on a sword wielding Satsuma Samurai) or any of the other early masters couldn't defend themselves? There is no doubt they were formidable fighters. And I just listed the "M" guys
.
The type of training they engaged in was rigorous two-man drills and solo practice with a focused combat mindset. For those who are not aware, original Okinawan karate consisted mostly of strikes to soft vital areas, grabs with locks, breaks and kicks taking out the knee. None of these are allowed in "sparring."
Many, if not most, of the early masters in the 1800's and into the 20th century were engaged as professional tough guys of one sort or another, often in life and death situations with criminals, pirates, or potential assassins. Yes, I think they were proficient without sparring.
The problem is most schools do not train like that anymore and people have been brainwashed that sport sparring equates with "real" karate. So, the answer to Tigerwarrior's question depends on which genre of karate you're talking about.