Safer and more efficient, perhaps, but better-made? We’ve encountered some evidence to suggest that even glass-lined steel tanks had thicker walls in times past than today. And they don’t hold a candle for longevity to copper or Monel tanks.
The only really recent safety improvement has been the recent adoption of a design to prevent accidental ignition of fumes, of which there were only a small handful of instances per year anyway. More efficient mainly means you can get a thicker jacket of insulation.
Water heaters that have been maintained as we advocate have lasted decades. And since, indeed, the design has been the same for more than 50 years, that makes them a better bargain than a new installation with plumber’s costs.