1 = NO its not = its all outdated!
2 = Which issues should that be?
3 = The ranking works very well, because everybody understands it.
Threema is unbeaten - up to this day - for nearly 12 years now!
Discussion
Lol no it doesn't work well because it's completely arbitrary, and you can't accurately determine the quality of multifaceted private messaging apps with a single metric.
This is marketing bullshit, not a legitimate system for evaluating the quality and strength of the different platforms. It's designed so that shills who have a financial interest in peddling a particular platform have a metric to point to to justify the sale. It's an instrument of security theater, and salesmanship.
Just let us know again if you have found any real errors!
You can also look at any other comparison tables - Threema is always number One!