I definitely agree. Closely matched cells would not really need that much balancing.
Matched on which parameter?
This is an important distinction when talking about matching.
To extract full capacity out of cells poorly matched
by capacity, you need a very specific form of redistributive balancing with:
1) Very high balancing power
2) Very high efficiency
This means shuffling charge with rate high enough so that the cell balance will be dynamically changed during one single cycle.
This is typically not much discussed (because it would be prohibitively expensive); discussion on balancing, including most discussion on redistributive balancing as well, is the "normal" sort of balancing, where cell capacity matching is irrelevant: the balancing power is used to only keep the balance at a fixed point (typically so that every cell is at 100% SoC at the same time). In this case, balancing current only compensates for the internal loss of charge in cells.
In these cases, cell matching by capacity is totally irrelevant from the balancing viewpoint.
Balancing is there to help with mismatches on:
1) self-discharge rate
2) coulombic efficiency
only.
Now, with self-discharge typically near zero, and coulombic efficiency near 100%, the absolute differences thereof will be very limited as well. If you have one cell self-discharging at 1%/year and another at 2%/year, even if they are relatively very different (i.e., non-matched on that parameter), the absolute value is still negligible.
I understand there are sources of low-quality (often not low-cost, though, even though people
think so) cells where there are significant differences between
capacity and/or
internal resistance. There parameters, however, are totally irrelevant for balancing.
Sadly, when any cell shows high enough self-discharge to warrant "efficient" redistribution balancing devices over simple resistive solutions (such as exceeding 20-30%/year), it's
highly likely that this particular cell is about to totally fail soon.
Simple dissipative solution will be able to prolong the life of some corner case packs with some cells starting to get "slightly bad", before they are over the edge of quick decay.