It's more a case that they have changed how grades are awarded.
Up until 1982 there were pre-determined percentages for how many of each grade were awarded eg, the top x% of candidates were given an A, the next y% of candidates were given a B etc.
That's a bit of an over simplification (it was a lot more complicated) but you get the idea.
After then it changed to "criterion referencing". What this means is that everybody who demonstrates sufficient knowledge or skill passes.
So, instead of it being a competitive exam (eg the top x% get an A) now it is more like exams for professional bodies, or even a driving test; anybody who displays sufficient knowledge will get the appropriate grade regardless of how many other people also manage to pass as well.
Again, it's a bit more complicated than that.
But there has definitely been grade inflation. Back in the 1980s around 9% of A levels were a Grade A and today the equivalent, A/A* is 25%.
The OP (I think) linked to some info showing that A star* *now accounts for about 8% of all A levels. So it seems like A star is the new A and A is the new B etc going on down.
But none of this answers the question are A Levels easier or harder today than in the past.
However, there was a study done in 2016 "Fifty years of A-level mathematics: have standards changed?" published in the British Educational Research Journal. This study looked at 66 exam papers from the 1964, 1968, 1996 and 2012 exams.
The result of this study was that the exams had got easier between the 1960s and 1996 but from 1996 to the 2012 there was no difference.
In 1996 the number of A passes had increased to about 15% and then by 2012 the number of A/A* passes had gone up to about 27%.
So, either people sitting A levels had got an awful lot more intelligent between 1996 and 2012 or there was some massive grade inflation going on.