It's mite be because it's gold rated it's tier 2 but the lists can be slightly misleading .I've seen the Thermaltake Toughpower GF3 1650 for under £300 which has two 12VHPWR but it is said to be a tier 2 PSU.
The noise is a real bone of contention imo was reading another review and they said psu of simmlar wattage are longer . This Probably allows better airflow and maybe more heatsinks so the fan doesn't have to work so hard.I agree but this time it's probably warranted.
The short hold-up time could have been an off unit in the review:
https://hwbusters.com/psus/thermaltake-toughpower-gf3-1650w-atx-v3-0-psu-review
The summary is a noisy fan configuration and it lacks OTP but there is much to like about it especially at sub-£300 which is available in a few places.
I think the best way to look at current ATX 3.0 PSUs is that they are a temporary solution until our next CPU/GPU upgrades in 2024/25 and decent 2000W+ ATX 3.0 models will be widely available.
It supports max 800W when using both 12VHPWR connectors and since I don't need to max out the 3090TIs, I run them at 350W each.
Are they open about these restrictions?
Yep, it's on their website and included on OcUK's product page about it.