The latest generation 18650 cell’s has a marginal larger capacity.
In my personal opinion that is caused by the ability to survive a deeper discharge (2.8V > 2.5V).
The remaining capacity between 2.8V and 2.5V is now useable without causing too much harm.
Though not for everybody and in all circumstances I think: an occasional 2.2V won’t hurt.
That is: if the discharge stops during the night and you recharge the next morning.
Because discharge is a chemical process. The current may stop, the chemical reaction can go on.
The longer the state of deep discharge lasts, the greater the possible permanent damage.
I would advise to test (all) your cell’s once in a while.
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If you prefer protected batteries, these SOSHINE 3,600mAh are the shortest 18650’s HKJ has tested