One of the big factors which people underestimate is the amount of capital they pay off if they have a cheap tracker.
If you borrowed €500k at a SVR of 4.5% over 30 years, 8 years ago, you owe €425k today.
If you borrowed €500k 8 years ago on cheap tracker of 2%, you owe €395k today.
SVRs were as low as 3% for much of the last 8 years. Even the cheapest trackers were over 2% of some of the last 8 years, so the above is a fair average.
Of course, if you had a cheap tracker, not only were paying off more capital, but your repayments were very low as well.