I already have Wi-Fi 7 device and tested at least 5 different Wi-Fi 7 routers. Here's some of my key TLDR findings

Wi-Fi 7 is not just about 6GHz. It enhanced the spectrum efficiency on 5GHz and 2.4GHz device as well.

There are Wi-Fi 7 devices without 6GHz band support in the market (Honor Magic 5 Pro). Similarly, you will see Wi-Fi 7 routers without 6GHz coming soon.

On a Wi-Fi 7 supported device used with a flagship Wi-Fi 7 router on the 5GHz band, you will get around 20-30% faster speed than a flagship Wi-Fi 6/6e router.

However, a flagship Wi-Fi 6/6e router will still outperform a mid-tier Wi-Fi 7 router on 2.4GHz and 5GHz.

Wi-Fi 7 on 6GHz is ridiculously fast at around 3000Mbps if it's within 5m line of sight, doubling performance on WiFi 6e.

Backwards compatibility is great, never had any issue even with my old IoT devices.

The best thing for now is probably the CPU upgrade. TP-Link Archer BE800 comes with 2.2GHz Qualcomm, ASUS is even ridiculous going all the way up to 2.6GHz Broadcom. Warn: All of them are hot.

Edit: All Wi-Fi 7 routers I tested currently are really stable, benefits older devices as well. All of them have the consistency of enterprise grade Wi-Fi access points, even on iPhone 12 Pro.

The main target is solving the selection of GHz, unsure will it solved the problem of bad configuration or not.

For example, my TM University having renew of WiFi like 6 years ago, they put too much AP and each other interference like butterfly effect, causing whole WiFi near shut down for most building, even 5GHz got issues(but still online), lucky Android phone can select/limit to 5GHz only at that time.
Final solution is they turn off certain AP in between as monitor mode, solved.
(The problem of too much budget, each small room each AP, with thin wall, lol )

So as u can see, if they really fixed the "Auto" as default issues, it surely bring down the setup and experience of average customer that know near nothing for WiFi.

But yes, that will be after 3 years, WiFi 7 have been supported by default on each smartphone la....