I would separate the marketing hype from the reality. I have a Fortinet business router and two Fortinet access points. I don't have it for speed, I have it because it offers virus and intrusion protection, which is needed for the home business, nowadays. Anyway my home has about 50 WiFi devices, Ring cameras, phones, iPads computers, Echos, you name it. I only bring this up because my router lets me see a graph of bandwidth down to the device level if I want. Long story short, even with multiple 4K TVs, I rarely ever see total bandwith for the home exceed 25mbps. If it does, its very short bursts. 802.11n or even g should provide all the bandwidth you will need. There are exceptions, of course, with PCs actually downloading files, but that occurs so little, its not worth mentioning.
In addition, these new WiFi standards have MANY MANY caveats. To get "full speed" you need multiple antenna support, not only on the router, but also the device. VERY FEW devices have more than two antennas. Oh, and that's not all. These WiFi standards need lots of bandwidth that you are sharing with your neighbors. There really are only 2.4Ghz channels (1, 6, 11) and only 12 in the 5Ghz band. Oh, by the way, if use many devices, they only support channels 36, 44, 149, and 157. Amazon Echos are one of these devices. (It has to do with radar interference migration, but that is another story.)
At this moment, my Fortigate can "see" a total of 149 other WiFi access points, many in cars. Only a few though are interfering with mine. Wi-Fi can travel much further than you think. I can "see" some access points over 1 mile away. (I live in the suburbs, not a dense city.) Also, do keep in mind that every "mesh" access point needs wireless backhaul that also consumes wireless bandwidth, so MANY times these mesh access points are actually slowing your speed.
The people that sell Wi-Fi equipment realize all these things, but they want you to keep buying and keep buying equipment. Making the latest Wi-Fi chips is cheap (I use to be in that business) so they churn them out hoping you will buy them. When you pay hundreds of $$ for all this stuff, you will learn that the new stuff is not going to make any noticeable difference.
To get the best speed and coverage, monitor your neighbor's networks, stay on different channels, and add a bigger, higher antenna if you need it.
Here is another "secret." Your phone has the worst signal of any device in your house, and iPhones are the worst. The phone's signal is ALWAYS a limiting factor on range and speed. Wi-Fi is two-way, and its the weakest direction that is the limiting factor.
When you get down to the realities of Wi-Fi, its not as pretty as the brochures for those "mesh" router networks.