Solar energy is actually flabby and watered down as it is typically delivered, especially on shoestring budgets.
When you have access to "mains" 110 or 220 VAC at 10+ amps, you trim it down and deliver it exactly as desired to charge your cells (within the budget constraints of how "smart" you can make the charger) in this scenario, the aged cells can probably be handled safely.
When you have 0.1sqm of budget solar cells delivering your power, and an aged LiIon cell as your storage medium, the electronics between those two are going to have to eek out every possible bit of power delivered by the solar side if you want a chance of the LED light lasting for more than a couple of hours after sunset. The saving grace here is that the solar cell _probably_ won't have enough power to make anything exciting happen in the battery, regardless of how you transform the voltage/current coming from it. The downside is that whoever is making the charger will probably scrap any cell safety considerations and just dump whatever they've got into the cell as "efficiently" as possible - and sooner or later the infinite number of users will hit on an operational scenario that makes it burn.