I somehow managed to completely overread this …
Generally, it’s probably very hard (if not impossible) to find reasonable metrics for comparing something like learning success, general progress, dedication or whatever between people, simply because there are so many factors involved (some learn quicker than others, some topics or languages are harder than others, this list could be continued ad infinitum).
When I look at Duolingo, there’s a zillion ways to quickly harvest XP if you’re inclined to do so, but possibly at the cost of learning not much or even nothing during the process.
Here on Memrise, there have probably always been courses that only serve for harvesting points. You could also create your own private course and learn nothing but earn many pointless points.
Do I care? No. Because I bet the vast majority is really learning.
Regarding motivation in general, comparing yourself to others is IMHO a very important motivator - for instance, think of courses created by teachers and geared at their pupils - there’s a ton of those!
Also, learning is a process where motivation is probably the single one major asset that makes people keep at it. Apart from intrinsic factors such as discipline and dedication anyway.
Streaks and competition are such motivators!
As to why your leaderboards might be “about as robust as a North Korean election”: I disagree.
Yes, Memrise also has different ways to earn points - speed reviews being the quickest and typing answers being the slowest (unless one just repeatedly clicks the hint-button). But still, leaderboards do show the dedication of the people learning resp. working through a course along with you.
I haven’t known Memrise from the start, but for around 6 years now and how points were earned used to be different.
If you ask yourself why it is like that, my personal opinion is that it’s the same as with many areas of Memrise: efficiency, options, variability and whatnot have continuously been taken away or simply degraded.
A very simple example: on Android, you used to be granted 50p for correctly “speed reviewing” an item and (up to) 150p for a typed answer, now you get 150 for both. Does it matter the way it is now? Not too much, I suppose, as it’s better than nothing.