Very few of the examples given particularly bother me. I agree the '75 years young' one is patronising (unless talking about yourself ). I noticed a comment about someone's DH being addressed as 'babe' by a waitress. Yes, that is probably inappropriate, though not offensive, just rather amusing.
But I found myself thinking, if I were a waitress and I couldn't address my customers as 'dear' or 'young lady/man' in case it was patronising, and I couldn't say 'babe' because it was inappropriate, and I couldn't say 'love' or 'pet' or 'sweetheart' in case they found it offensive, then I might feel as if I were suppressing my natural friendly approach, which would in turn prevent my engaging with the customers in any 'real' way.
We all tend to hate the kind of scripted conversations common with faceless call centres, and I fear that if this so called 'ageist language' is promoted as offensive and people we meet in bars, restaurants, cafes, shops etc. are trained not to use it, our lives will just become even more sterile and sanitised.