There are a lot of reasons that ordering a car is better than picking off the lot.
And also in my current situation, the exact color combination I want is hard to find on the lot.
For Gold Coast Silver paint with the V8, interior color, and wheels that I want, there are only two in the USA. One dealer unwilling to budge from MSRP, the other is doing $2,500 off but they're in CA which has weird tax rules, so I'll have to pay an additional $1k for shipping, making it effectively $1,500 off.
The factories aren't manufacturing GCS paint anymore, so Savile Silver is my second choice. For 5.0s with the interior color & wheels I want, there are only one or two on dealer lots in the USA. Neither of those are discounting much.
So this $5,500 off is the best deal that I've seen so far after calling about a dozen dealerships (that was about what they had in stock on the lot). That dealer does also have a 2021 model for $7k off. They have the most competitive pricing in the nation based on my experiences. There's no shortage of G90s; nobody buys them and production hasn't been affected much. But most dealers are still raising the prices on them to around MSRP due to the general new car shortage.
Additionally, the one I'll get will never have been test driven. More importantly to me, I can have the dealership make sure that they don't 'detail' the car when it's delivered, so I'll get the paint as it came from the factory without having dealerships ruin it when they wash the car. If you care about not getting micro-scratches in your car (look at an old car on a sunny day, you'll see tons of scratches on it, every time your dealer washes the car they put more scratches in it) then this is very important. I'd be willing to pay $500-$1k more to get a car ordered vs. picking one up off the lot for this reason alone. But in this case it's the opposite; ordering is the cheapest deal I've found.
Finally, regarding the 2023 models. I don't want a 2023 model. The first model year of a new generation inevitably has issues - on any model of any make; even Toyota with their legendary reputation for reliability isn't immune from this. On the G80/GV80 forums you can see threads about recalls already. The issues should be covered under warranty, but I don't want to have to deal with the hassle of taking my car in, and I don't want to have to deal with Hyundai dealership service departments, and there could also be bigger issues which can't really be resolved after the car is manufactured. For example Honda has oil dilution issues on their 10th gen 2016+ Civics, and the CR-Vs with the same engine; that issue wasn't really resolvable for the early model year cars. But they did tweak the design & programming of the engine over the next few years and my 2020 Civic has all those changes included. I'd want to wait at the very least until 2024, which aren't being released until 2 years from now. I don't like my current car and don't want to wait that long. And if there are more significant issues found, like the Honda oil dilution issue, I'd want to wait even longer for Hyundai to resolve all of that before I get a G90.
The manufacturers also do minor changes/upgrades between years. For the G90 not much has changed from 2020-2022, but there are small differences between 2020 and 2021. My 2020 Civic Si Coupe was the final year before Honda permanently discontinued it; each model year from 2017, 2018, 2019, 2020 has had minor but notable changes made to it. My 2020 is the most refined and best Civic Si Coupe to ever have been made. Genesis has been making changes to trims between model years for the new G80; if I get the 2024 G90 I'll miss out on these small upgrades made in future model years. With the 2021/2022 I'm getting the best, most refined version of the 1st gen G90 with all the bugs & kinks worked out.
The current gen's only issues are that the interior design is outdated, and it has an analog instrument cluster, and the quality of the buttons/switchgear/knobs is far inferior to the new gen G80/etc. Which overall isn't really a big deal when you think about it. The analog dash might be ugly but it's perfectly usable, and having better feeling buttons is nice but not that important. The new gen also has a few downsides - it doesn't have the V8, it has stupid retracting door handles, and it seems to have a worse dash layout/design from the leaked photos, etc. The leaks also show that it has massive 20/21" wheels which is really bad. Those disadvantages outweigh the full digital dash and better buttons, and by waiting for the new gen you risk Genesis also making other bad changes that we don't know about yet. Like with the 2022 G80 - to get all the good features like 3D instrument cluster and noise cancelling, you have to go for the "Sport" trim which is the opposite of what I'm looking for. What if Genesis gives the new G90 the same treatment? Then I won't be able to get the car that I want; I'll have to either compromise for less features or get more features but have the ugly sport design (carbon fiber trim) and suspension tuning.