You mean "nominal terms" not "absolute terms".
Real terms is much more meaningful as the value of £1 is determined by what it can buy not what number it's denominated in. It's not a perfect metric and open to interpretation (eg do you use CPI or the GDP deflator) but it's far less arbitrary than the number of currency units of declining value (declining at a variable rate).
Your example of mortgages is just wrong. The measure is like for like, not tracking the pay progress of an individual through their career.
Mortgage rates haven't gone down but have gone up and house prices have gone up by more than inflation, so a new teacher, nurse or Junior Doctor today will have to spend more not less out of their take home pay than in 2010.