Lets talk about Wifi 5 Routers and key difference with respect to Wifi 6 Routers

IEEE 802.11aac standardIEEE 802.11ax standard
Only 5ghz band is used as wifi 5
2.4ghz is separate as N network
2.4ghz + 5 ghz is integrated into single network so you get both bandwidth and coverage auto optimised
Uses more battery if connected to 5ghz Uses Target Wake Time to connect only when required saving battery
Less no of device can be connectedDue to OFDMA 50% more devices can be connected to same spec router
old N/G devices can be connected as 5ghz AC network is separate.All devices need to wifi 6 supported to fully use wifi 6 capability. The moment any old device is connected it starts behaving as separate 2.4ghz and 5ghz wifi 5 network router.
All wifi 5 Wifi 4 wifi 6 devices can be connected Only wifi 6 devices for wifi 6 benefits
cheaper to setup as only router is neededcostlier as router along with all clients need to be upgraded
Bss colouring not supported so congestion is formed if too many networks in same placeBSS colouring supports helps identify from other networks to reduce congestion

Wifi 5 network is almost end of service. While wifi 6 has been extended to wifi 6E where another 6ghz frequency band has been added to support for multi-gigabits speed over wifi networks.