@ChrisF60526 - Focusing on specifically answering your question here.
First off, do remember, Wifi 6 is more about gains in
efficiency at scale than it is throughput per client (the one thing the average consumer looks for the most). That being understood, it's highly unlikely Wifi 6 will offer any real-world improvements for you, at least not until the bulk of your client population is AX-only. Even then, the items most required, namely OFDMA, symmetric MU-MIMO and target-wake-timing (TWT), probably still won't be enabled or usable in the vast majority of APs and clients (and many might argue for the life of the spec). The only benefits you
might see today would be up to 2X the throughput in 2.4Ghz for AX clients only and up to 2X the 5Ghz throughput if you're able to use 160Mhz channel width (often tough due to airspace restrictions and/or saturation). For more on the specifics of what you can expect from Wifi 6, and an excellent grounding on the priciples of wifi in general, see this awesome
Duckware article, specifically section
11 (Wi-Fi 6 (802.11ax) 5 GHz (HE: High Efficiency).
Those are the differences on the
wifi spec alone. That's it. That's all. Beyond that, any supposed "benefits" tend to be attributed to items that, especially in the consumer space, are often
combined with AX wifi, but are
not wholly exclusive to it -- I'm talking about faster CPUs, beefier switches, better board designs, better firmware, etc. In other words, there might be plenty of reasons to upgrade to AX-class Asus hardware, but Wifi 6 on its own isn't really one of them, despite the portrayal by those who may be less familiar with or just glossing over what is going on from a pure wifi perspective alone.
Per
@thiggins reply, you'd probably be best off saving for Wifi 6E gear, which will offer actual new spectrum (and require new radio hardware for it). That being said, 6Ghz will be even less interference-tolerant than 5Ghz, probably best for in-room and/or line-of-sight applications only, ie. a substitute for a short-distance wire, so you'll want to plan for it accordingly when the time comes.
An additional consideration when it comes time for a hardware upgrade would be a move to SMB/community-grade discrete components (ie. separate router, switch(es) and APs), which, beyond and above consumer hardware, would offer PoE, native VLAN awareness and utility-grade runtime straight out-of-the-box. This would be your go-to gear if you wanted to centrally distribute power with data, increase your skill set and/or just wanted a more appliance-like network. Short of any of that, though, I'm sure the next round of Asus hardware (with Merlin firmware) would suffice well enough.
Hope that helps give you some perspective.