There are two technologies used in etching, UV and EUV. UV was designed for nodes upto 40 nm (approx). EUV can be used with accuracy of 13nm. EUV has been under development for more than a decade in several firms, so companies used several trickes to make use of UV for lower sizes. 10nm is the extreme end of it (I guess). For EUV this is standard range. It should work without any issues until 5nm and then special tricks would be used to make the pitch smaller.

So manufacturing 10n, with UV is much harder than manufacturing 7nm with EUV (although it is more expensive).