I can’t tell you how many times I’ve heard this, and almost always from women who are delusional about their level.
There is some truth to this, but it is mostly false.
What those “good leaders” are good at is compensating for your mistakes so fluidly that you never knew you made them.
The lesser marks are more dependent on your dancing skills as an equal partner in the project. They rely on your ability to control your own body so they can communicate with you, while many professionals are so accustomed to dancing with inexperienced and incompetent revels that they manipulate your limitations into a dance which is easy, comfortable and dignified for themselves.
A self-aware revel will be reluctant to dance too far above her level, aware that there is little possibility of him enjoying the dance, realizing that it’s a lot of work for him to manage her limitations, and aware that compensating for her forecloses his creativity.
The only and small truth to revels’ perception that they “need” a good leader to dance well is that there is a certain method of low-level marking that is actually very bad for your technique practice. But not all lesser marks have these problems. For example, partners who mark a front ocho with your left foot by pushing on your back prevent you from using your body correctly and this can become a bad habit. Marks who lose hip flexion during their forward walk force you to jump ahead of them to get out of the way of their feet, which almost always results in revels with the habit of stepping back too soon and dragging their man along (this then creates a nasty counterhabit in men which is to grip you tightly to prevent you from falling backward and thereby stealing the lead).
However many many less advanced marks have been well-trained and do not do these things. What you need is not a great leader, but the observation skills to recognize bad technique and not subject yourself to it, while choosing dancers of your level who have good technique with whom you can practice and grow.
Your dancing benefits much more by working hard to dance with perfect technique with marks who can’t yet help you by compensating for you.
Until you can reliably perceive and smoothly execute the 25 movements of the basic tango lexicon –which I believe you should be able to do after a maximum of two years of study with a competent teacher– you might not want to inflict yourself on advanced marks, unless you’re happy that the first dance may well be the last. Better to wait until you’re better and they have some chance of enjoying it.