Currently, for a Mac Studio, Studio Display, mouse, keyboard, it comes to about £3,750 GBP here in the UK ($4,785 USD ish)
...actually, the US price is more like $2000 (Studio) + $1600 (Display) + $150 (Keyboard) + $100 (mouse) = $3850 - remember that UK prices include 20% VAT. OK, some of us have to
pay the UK price but if you want to compare things it's easier to stick to US prices.
Spec-wise, it's impossible to really compare like with like, but the M1 Max Studio, at launch, was probably comparable to the top-end i9 iMac. On things like I/O capacity it was half way between that and the $5000 iMac Pro. The Studio Ultra is more in $7000+ higher-end iMac Pro territory. The top iMac was $3199
plus $600 for the upgrade to 32GB RAM. (OK, cheaper RAM was available, but that option was always going away with Apple Silicon).
So the only real loss has been the lowest-end, sub-$2000 5k iMac - now you have the option of a Studio Display + Mac Mini starting at $2300 - which will probably run rings around old entry-level 5k iMac.
And does the MacBook need to be opened, or can you close the lid?
Up to you. You can get third-party stands for both configurations.
With the regular-M3 MBPs you can only drive two displays total, so you have to close the lid to run dual displays. Non issue with the M3 pro/max chips.
I used to use a laptop with an "elevator" stand to keep it open and level with the large external monitor so I could use both screens.
These stats are no more correct than those which claim Apple only sells a handful of Mac Pros per year. Do laptops outsell desktops? Absolutely. Is it 9:1? Unlikely. And even less likely is that the MacBook Pro outsells (handily, at that!) the “most popular laptop in the world”…
I don't think anybody doubts that desktop sales are a small, and declining, fraction of laptop sales - ISTR Apple came up with the 1-in-10 figure back in 2017 and it probably hasn't gone up since then - so the 9% in the CIRP data is probably on the optimistic side.
However, I wouldn't give the time of day the actual figures and breakdown between models in that chart. No confidence intervals, no details of methodology, no dimensions (is it unit sales or revenue? both are common) => not worth the pixels it is rendered on. Then add the overall implausibility - if those were the actual unit sales its doubtful that Apple would bother making those models.
Being based on revenue would explain a lot - e.g. each Mac Pro equals 10 Mac Minis worth of revenue - but we just don't know. I suspect the low-end, regular M3, MacBook Pro sells in quite large numbers, or Apple wouldn't have such a large overlap between the top-end Airs and low-end Pros.