Same here. 12 core processor, NVME, clean OS, enough memory to make Altman furious, and Excel still starts slower than Calc did when I was running it off spinning rust and a Core 2 Duo.

Fortunately, I get to do what I want with that rig, so 95% of the spreadsheetin' I do on it are on Calc. Excel is only there for the rare compatibility issues and checking the occasional Calc-generated .xlsx that I have to pass on to others.