Anyone who uses a traditional WiFi extender knows that sometimes you need to change devices to the extender's own WiFi network when you are too far from your wireless WiFi router. This is mainly because WiFi developers have their own network name that is slightly different from the name of your wireless WiFi network. For example, an extender's network name may be the name of your main network with the letters "EXT" tagged on, indicating that it is your extender WiFi network.
Mesh systems like Eero, on the other hand, automatically help your devices switch to the nearest Eero, and each Eero transmits the same WiFi network name.
Eero also automatically connects your devices to the appropriate WiFi band ̵
To be fair, some new extenders provide the ability to keep your main WiFi network name and band to make switching easier and automatic. At the same time, you may need to enter the extender's settings to activate that function, which can be complicated for many users.