"Is tape still used for backup? Why is tape still being used these days when disk and cloud are available?"
Cue an avalanche of fascinating pro- and anti-tape pitches and opinions. Wading through the comments may take a while (I pitched-in with a couple of comments too) but it's a useful read as, frankly, these are the questions that clients/customers/decision-makers - and indeed ourselves - should be asking to ensure that we continue to use the right technology for the right purpose.
Of course, TSM itself is well-positioned for in many ways given its long-running support of disk, both in random access and more recently in sequential file (virtual tapes!).