You can definitely use a 5V 3A charger with a 5V 2A device without any issues. The important thing to understand is that the current rating of a charger represents its maximum capacity, not the amount of current it will constantly supply to the device.
When you connect a device to a charger, the device itself determines how much current it will draw from the charger. The charger simply provides the necessary voltage and the device takes what it needs. So, even if the charger is capable of supplying 3A, the device will only draw 2A because that is what it requires.
Using a charger with a higher current capacity than what the device needs is actually beneficial. The charger will not be operating at its maximum capacity, which means it will not be under stress and will have a longer lifespan. It will also have some extra headroom in case the device requires a little more current at certain times, such as during high-power tasks like gaming or video streaming.
I have personally used chargers with higher current ratings for various devices and have never encountered any problems. In fact, many manufacturers themselves provide chargers with higher current ratings to accommodate a wide range of devices. It’s always a good idea to use the original charger that came with your device, but if you need to use a different charger, make sure the voltage matches and the current rating is equal to or higher than what your device requires.
To summarize, using a 5V 3A charger with a 5V 2A device is perfectly safe and will not cause any harm to your device. The device will only draw the current it needs, and the charger will operate within its safe limits.