There is really only one camera out there that can compare to Z9 performance/MPs for less cost and that is the Canon R5. However, it does have some limitations compared to the Z9 because it lacks the stacked sensor. But it also has some benefits over the Z9 including better BEAF, a better suite of AF modes (IMO, YMMV) and much better rear buttons and better options to customize those buttons. It also has a nicer EVF excepting the slideshow. The Z9 has a number of features over the R5 like the slideshow free EVF, selectable FPS in ES and I do like having the built-in grip most of the time although sometimes it is nice to have the option to go grip-less.
I think the current pricing tiers are in line with the performance/MP/stacked sensor features in each camera. The R5 lacks the stacked sensor so deserves the lowest price. The R3 lacks the MPs but I believe has better AF than the Z9 (I haven't tested the R3 yet...will have it on April 1st) and has the stacked sensor. I think it does justify its $500 higher price. The A1 has everything...best in class AF, best in class customization, stacked sensor, highest AF calc/s, highest res EVF, highest FPS at high res, highest EVF refresh etc. So again I do think it justifies the additional $500 over the R3 and the $1000 over the Z9. Future Canon R1 if high MP and fast stacked sensor with built-in grip may justify the likely $7000 price it will ask. You do also have to consider cost of battery grip for better ergonomics with R5 and A1 but those can be had fairly cheap used and then some people don't even like using them or just want a small pinky extender plate for even less additional cost. So as always YMMV.