On EE here along with my immediate household. £20 each (24.11USD) for me and £16 (19.27USD) each for additional lines for wife & son gets us 120GB 5G data each, along with unlimited voice/SMS (not that we use much of the latter two). The cost includes tax as well. Decent 5G coverage for son & I on iPhone 12 & 13 Pro respectively, wife constrained to 4G on her 11. These are 24 month SIM only (service only) contracts, as our phones are bought directly from Apple.
If it’s any consolation, a number of us Brits wince when we see what the US carriers charge (AT&T & Verizon especially). There’s an argument for us having less geography to cover in cell towers, but even still.
On the EE Apple One thing, it looks like this is only for monthly contracts that include buying an iPhone direct from EE. Was hoping that I might be able to snag Apple One Premium at a slight discount from EE rather than the £29.99 I pay Apple per month. Not to be though - EE supplied Apple One is individual only, and as part of a handset inclusive contract.