As long as you dont provide any reasoning your are just another guy in the internet talking gibberish.

1. The throughput is inadequate.

2. The IDS/IPS is an inadequate Suricata instance with outdated rulesets and no SSL inspection.

3. There is nothing comparable to a WAF.

Gun to my head, I'd trust ASUS AI protect for a business router to substantially outperform Unifi's security offerings.

The ASUS at least knows what it is and what it can be: basically a glorified WAF. IDS/IPS don't even work well with up to date rulesets if they can't decrypt traffic.

“Inadequate” depends a lot on what you’re doing. I wouldn’t use any of this stuff in a datacenter but for a small business or branch office it’s totally fine.

What kind of small business actually benefits from an IDS/IPS or WAF?

Feel free to flog their network engineers. Most businesses (likely in the order of 99%) have precisely zero network engineers. So, it’ll be a pretty quick flogging.

Their products talk to those businesses.

You are forgetting that most business' needs are extremely minimal. By volume there are more bakeries, bars, gyms, one man doctor's offices, little car dealerships, hair salons than businesses that have actual IT needs. And for those businesses a dream router is fine if not a bit overkill.

Every small business within driving distance of me seems to have Ubiquiti WiFi on their walls/ceilings. Seriously, in the businesses where they provide free customer wifi these things are everywhere.

Likely UDM Pros and not Dream Routers. Businesses still want it to look professional with at least a 6u wall-mounted rack.