Basically all your objections boil down to the fact that the UniFi's are not very easy to manage.
I'd say none of this matters if you just want to have a few access points around the house for a WiFi network that currently runs on a single standalone router. Nobody said configuring the UniFi's is easy or convenient, but the premise is that you only do it once, using whatever computer you have that you can install the cloud controller on. You don't absolutely need to buy anything besides the AP's, it's only for convenience if your network changes a lot.
I'd say none of this matters if you just want to have a few access points around the house for a WiFi network that currently runs on a single standalone router. Nobody said configuring the UniFi's is easy or convenient, but the premise is that you only do it once, using whatever computer you have that you can install the cloud controller on. You don't absolutely need to buy anything besides the AP's, it's only for convenience if your network changes a lot.