Statistics are largely irrelevant here. The game was played to a far higher standard (fielding excepted) in the 90s, particularly test cricket, although I wouldn't expect most millenials to understand why. I would suggest you watch what a forty year old Shoaib Akhtar did to Sangakarra in that masters match not so long ago. Cricket in the noughties has been reduced to baseball and if you believe that short boundaries, slow flat pitches, huge bats with amazing pick up, and garbage bowling attacks blessed with the ability not to move the ball off the straight constitutes a test of cricketing mettle then we'll have to agree to disagree. I'm pretty sure the chap affectionately termed MoYo on here would be averaging more than Steve Smith if he'd been playing for the last few years, I don't think the latter would've made the team with his method in the 90s or earlier. Inzi all the way, certainly in tests.
Plenty of mediocre batsmen have scored runs against Akhtar in his pomp, and in 2002, Sangakkara scored 230 at a SR of 70+ against an attack of Waqar and Shoaib, when Shoaib was at the zenith of his career.
Hence, I am not sure about the relevance of your example. Sangakkara struggling against a 40 year old Akhtar for a couple of overs in an exhibition ground means absolutely nothing. He has toyed with the best bowlers in the world, unless you are suggesting that a 40 year old, long retired Akhtar is better than the contemporary world class bowlers, in which case one wonders why Akhtar retired in the first place.
Inzamam was a great player in his own right, but he would not be averaging 60 today. The weaknesses in his game had nothing to do with the era that he played his cricket in. He was a very good player of pace, but an average player of bounce. Hence, that is why he had a mediocre record in Australia and South Africa.
He struggled against Donald and Pollock in South Africa, and he would struggle against Steyn and Rabada today. As far as MoYo is concerned, he is underrated on PP, but they were glaring weaknesses in his game as well. A magnificent player of lateral movement, but he was average on turning pitches. Smith's ton on a rank-turner in Pune is the type of pitch on which MoYo struggled throughout his career.
Pitches have been flat in ODIs since the 90's, and some of the Asian Test wickets in the 90's and 2000's were flatter than what we are seeing today. The difference in ODI cricket today is that batsmen are more inventive with a wider array of shots. The likes of Jayasuriya were revolutionary in his era because he was ahead of his time; unlike other openers of his era who opted to see off the new ball, his modus operandi was to make the new ball fly.
A lot of deliveries that were respected by the batsmen of yesteryears are now deposited to the boundary. Starc, Boult, Rabada and Hazlewood etc. are world class bowlers by any measure, and even they routinely get smashed because of the paradigm shift in the mindset of the batsmen.
It is a myth that the great bowlers of the previous eras would be taking wickets for fun today. They would routinely get smashed as well, because majority of the batsmen of their time did not have the mindset to punish their bad balls like the batsmen today.
