Ubiquiti has some higher end products, but Unifi is their home/SOHO product line.
People can dedicate a small cabinet to UniFi rack-mountable gear plus the network center of their house. TP-Link has none of those, and not aiming for that market, even.
It's comparing a Peugeot 3008 with a Mercedes-Benz G Class and adding that, Mercedes has serious off-road trucks like Unimog, but G Class is their end-user product.
Apples to Pineapples.
BTW, it's not hard for me to install and manage a high capacity UniFi network in any way. I don't use their devices, because I don't want to manage yet another network.
From my experience, TP-Link makes hardware changes with "H/W versioning" in their model numbers. I have many RE220 extenders with different hardware revisions, earlier ones doesn't supporting OneMesh. However, I don't find later versions performing worse w.r.t. earlier ones.
However, $500/unit, the backbone of the devices doesn't look underpowered, esp. when looking to both wireless and wired specs. Considering my RE700X is saying what's written on the tin, and being rock-solid despite working with a non TP-link device and and being behind two 30cm walls.
I expect these Deco devices to live up to their specs.
Not convinced that’s “home” or “soho”, unless you have a very generous meaning of “small” which leaves the 5 person office somewhat undefined.
Even our largest buildings at of multi billion dollar revenue company only get upto 2500 wifi devices.