No. Mains water must meet more than 55 quality parameters and is perfectly drinkable. In addition, after a certain period of use, these devices can alter the quality of the water.
Activated carbon filters are usually attached to the tap or placed in a kind of jug containing filter cartridges. The filters found in these jugs are most often a combination of activated carbon and ion-exchange resins to soften the water. In most of the small activated carbon filters, there is a significant bacterial growth after a rather short period of use. The water that comes out of these filters therefore has a poorer bacteriological quality. And when the filter is saturated with the adsorbed substances, these substances can, in some cases, be released into the water in much higher concentrations. A regular replacement of the filter cartridge is therefore necessary.
Membrane devices (reverse osmosis, …) are most often placed under the sink. In addition to potential problems of bacterial growth, these filters eliminate substances that are beneficial to our body, such as calcium and magnesium. They also lead to water waste.