However wage inflation can be a different matter. Wage inflation in Ireland from Q4 2019 to Q4 2020 was 4.8% see here https://www.cso.ie/en/statistics/earnings/earningsandlabourcosts/
At the individual level many people have increased earnings as they age due to promotions etc.
This points to the idea that the burden of repayment falls as the years go by.
The possibility exists that inflation as measured by consumer prices will not be as low over the next 20/30 years as it has been over the last 20. This would increase nominal wages but not nominal mortgage balances. That would make deferred payments less of a burden.
So I suggest that wage inflation, and possible price inflation are reasons to consider extending a mortgage term as long as possible.
Be careful here.
Recent wage inflation may be partly due to compositional effects.
COVID has hit low-paid workers more.
As they drop out of the labour force, average earnings rise, even if everybody else remains on the same wage as before.