Oh man 9 hours of excel, that's insane, i remember doing a few hours back in the school and that was more than enough!
About the focus, it's nearly impossible for me to totally focus, at work there is a big office with 8 people in, so there's always noise, someone calling you, and I'm not high ranked that I can whine and such, at home work they write me on teams and I can't ignore them so... Off work I can, but not many hours, I do similar to you, no phone, just sit and do what I got, once in a while a little break even just to do a walk in the house
Noisy offices can be bad for maintaining focus but I also am not convinced that working at home in silence is the best either; I've always promoted team environments and have worked towards each person being respectful of the others; easier said than done I guess sometimes.