I am in a 2 bedroom apartment, I tried to use xfinity compatible modem got it refurbished from amazon CM1000 ( Netgear) .
I am measuring it by performing Speedtest.net test , also using DNS as 1.1.1.1
I am using it wirelessly though iPhone XS and MacBook pro ( all ac capable) I have been at a college campus before and achieved 900 mbps download ( wirelessly !!) so why can't I have that at home ?