The standard PADI course still uses either the tables or the eRDPml--the calculator-type device. The eRDPml gives the same results as the tables, but you are not going to be making the most common table errors of reading the wrong column or row. The eRDPml also allows you to plan multi-level dives, just as the wheel did.
It is possible for a student to select a computer-based OW course instead. In that case, the curriculum is different. It goes quite thoroughly into the use of a computer, including using one for dive planning.
It is correct that the standard PADI curriculum does not include gas planning, figuring that in standard recreational diving, a diver simply needs to monitor air pressure and ascend at an appropriate time. (I am among those who believe more should be taught.) PADI has approved an advanced dive planning distinctive specialty that includes gas planning and much, much more. You will have to find an instructor who is certified to teach it, though, and there aren't many. The plans are for the academic portion of that class to be available on the PADI web site in the coming year.