In other words, the simpletons who mistakenly believe they understand the problem, just don't understand what the "..." notation in the number 0.999... means. The "..." indicates the operation of a LIMIT. So, the simpletons MISS the point that 0.999... is not just a number as written, but it's a FUNCTION in disguise. As we know, we operate functions in order to arrive at results.
Once you understand that, the next determination you need to make is DOES IT CONVERGE. Yes, 0.999... does converge. Then, the next thing is to determine which SINGLE VALUE the limit converges at, assuming infinity is reached (which for a number line, is always TRUE). The single value is ONE.