The amount of oxygen produced by live plants does very little to improve the environment, it will not increase the number of fish you can stock. They do remove nitrates from the water but regular water changes will do this just as well. Having live plants can reduce the likelihood of your tank being swamped in disgusting algae, by using up the nutrients the algae needs. however planted tanks can still become algae bombs and many non-planted tanks never do.
Real plants do take more work, most need fertilising, some will not survive without CO2 diffusion (which can harm fish). They need pruning. The plants you buy are usually plump and healthy, but you will find they grow stalky and thin if not very well cared for - they may survive but will look awful. It can also be hard to get true aquatic plants - people sell terrestrial plants that will not survive long underwater. No matter how well you look after them you will not be able to keep them alive in aquaria.
There are some very realistic fake plants which are just as good at sheltering fish as real ones and will not be eaten by your fish. They can be expensive if you choose realistic looking ones. They also need the odd clean or they are covered in algae and look unrealistic.
The other advantage of fake plants is that you can use them in tanks with fish that eat live plants.