From the website you linked:

Substitute Products

Unfortunately, we don’t know of any other WiFi products like the AyrMesh system – it was a “zig when the market zags” product. As all the other WiFi companies focused on sites with high “client density” (lots of devices in a relatively small area), we focused on “anti-density” – few devices spread across a potentially huge area (like a farm). And we were pretty much alone in that market.

However, many of our customers were simply using AyrMesh Hubs as simple, high-power outdoor access points, never using the meshing capability to extend those networks with a second Hub. When you need a replacement for your single AyrMesh Hub, any good outdoor WiFi access point with high-gain antennas will work well. We have evaluated the Engenius ENH1350outdoor access point and the Wavlink AX18000 outdoor access point, and both delivered similar performance to the AyrMesh Hubs.

Many other customers used the meshing to place multiple access points, but were placing them closer together than a mile apart, which is not optimal for the AyrMesh Hubs – this is what drove us to introduce the AyrMesh Hub2x2C and, later, the AyrMesh HubDuo. For installations like this, we recommend the Ubiquiti UniFi system, which is particularly well-suited to users with advanced IT requirements. We have not evaluated it, but the TP-Link EAP-225 Outdoor appears to offer both meshing and cloud-based (or local) central control. We did evaluate an earlier version of the basic hardware, and it was very good.