I might be mistaken but are not mobile numbers in the UK in their special area code/exchange so calling them costs extra? Calling landlines does not seem to be

I might be mistaken but are not mobile numbers in the UK in their special area code/exchange so calling them costs extra? Calling landlines does not seem to be profitable anymore (my home landline gets almost 0 calls now, my work phone gets maybe 3-4 calls a week) so the scammers only want to call mobile numbers and in the US it's not different from calling a landline while it might cost extra in the UK.