While it seems logical do use the same SSID on all bands on the same AP, it often doesn't work that well. And I mean 2.4GHz in particular. Today that band is over occupied and in my experience, whenever a device switches over to 2.4GHz the performance drops even though the signal strength looks better. The 2.4GHz frequency band is over occupied with wifi (wireless mesh and or repeaters), bluetooth, thread, zigbee stuff and many other wireless devices.
I for one have limited the 2.4GHz wifi to single channel mode and is only in use for a few IoT devices that do not need high bandwidth anyway. This way the disturbance I get from neighbours is reduced. All the high bandwidth Mac's are on 5GHz.
Just like the 5GHz band was kind of empty 15 years ago, the 6GHz will probably be relatively empty for the coming 5 years. I'll wait a few years until I replace my Zyxel WAX650S, when the 5GHz becomes overcrowded too. Maybe when wifi 8 is introduced? 😉
I haven’t tried to go 5GHz only for a while, might try again. There’s always one pesky old device that it turns out I still need. Lowest common denominator wins again.