Mesh networks do have the benefit of being a nice simple plug and play system and they can have great performance. But they definitely should not always just be the thing you immediately jump to for network expansion.
There are other ways to achieve the same thing, some of which are free if you have the right stuff laying around from a past upgrade.
Personally, I like to tinker and one of the benefits of upgrading quite often is that I usually have a spare router or two kicking around.
The whole "you lose half your bandwidth" argument for using an extender is true. Or at least it is for the nasty ones you usually see in most stores. The reason they reduce your bandwidth is they use a single radio to both receive and transmit. Avoid them at all costs. The ability to extend a WiFi network without speed loss has been around far, far longer than a mesh network. Specific hardware has been around to do this for many, many years.
Using a good WiFi repeater with two radios, one for receiving and one for transmitting. Means you have no halving of the available WiFi bandwidth whatsoever. It's essentially the same kind of system adopted and popularised by mesh networking.
If you're a tinkerer and have a (compatible) spare dual radio router, then installing dd-wrt and setting it up in client-bridge mode allows you to do the same thing you achieve with mesh networking.
Of course, thats not for everyone. I mention it merely to give food for thought to anyone wanting to extend their network without necessarily having to spend any money. And to dispel the whole, you lose half your speed myth.
For those less inclined to tinker, or don't have the hardware, there are low cost repeaters specifically designed with two radios to do the same thing. Even something like the Hawking HW2R1 does a stellar job of repeating a WiFi signal, without bandwidth degradation.
Oh and there’s the added benefit with both of these methods of not being locked into a single manufacturers product line.
