@amnesia2, as usual, the details matter here.
What is the actual cost to you to move to 10Gbps Fibre?
Depending on that objective cost, a GT-AX6000 as a main router and your current RT-AX86U as a wired node (via the 2.5GbE Ports) will provide a noticeable improvement to all your current devices and will decrease the latency by a factor of 2.5 times too. If you have any wired-capable 2.5GbE devices, an additional switch will be needed too (and maybe two of them if your 2.5GbE devices are not all located near one router or the other).
While the 10Gbps plan may seem 'wasted' with 2.5GbE equipment, depending on the cost, it may still be worth it in the end. And, after the contract period is over, you can still fall back down to a lower tier at any time too.
Removing the RT-AC86U from your main/AiMesh network will also give you a lower latency network. If you want to continue using it, I'd suggest using it for any wired-capable devices in Media Bridge mode (even if you don't change plans today).
Don't believe you have one choice in this path. There are many things to consider.
So, what will it actually cost you to change plans today (ISP charges)?
With the ISP plan in place and a solid upgrade from your current 1Gbps speeds (are they symmetrical?) you will be in a great place to wait for the WiFi 7 equipment to become available, stable, and ready to be tested in your environment at your pleasure.
There is no 'need' for greater than 50 or 100Mbps plans for most people, but if the cost to go to 1Gbps is negligible for their budgets, then not upgrading is hurting them in the long run. Whether they realize it or not.
If you're able to secure a trial period (for both the ISP increase and return policies on the router), then do so. That is the only way you'll know if the benefits are obvious in your networking environment and use.
Good luck.