A lot of manual settings with obvious features (NAT acceleration, NAT loopback, good VPN client, easy QoS, reasonable firewall) being extremely hard to configure well in comparison to competing SOHO equipment.
Opposite way is much harder, as we can see with Ubiquiti: they hide and remove options, that are needed. With USG devices, I could have config.gateway.json configuration for some of those hidden options (like having site-to-site VPN using hostnames instead of IP addresses... well, Unifi UI cannot do that, but strongswan doing the IPSec on Unifi has no problem doint that). With UnifiOS devices, they are not addressing the issues, they are taking away the workarounds instead.
So they can advertise as much as they want, until they make devices fit for the purpose, there's no point in purchasing them. I don't see the situation improving anytime soon, they don't listen on their own community forums.
I think it's one of the better standalone WiFi router/AP's out there. If you want a long term supported open source/openwrt one it might be the best choice out there.
The original 3.11 release track has been super stable for many years, and is still being updated with security fixes. The 4.0 branch was a bit bumpy ride but since the 5.0 release early last year I've had zero issues.
Note that the default WiFi chipset is not the latest generation, and although the dev team is actively looking at the possibility to get some wifi6 working [1], I think it might be a while before that is out and stable.
As a bonus it has some cool features like built in support for CZ.nic's honeypot as a service [2] and lxc.
[1] https://forum.turris.cz/t/wifi-6-ax-adapter/10390/63 [2] https://haas.nic.cz/