Bottom line.....this video is a satire directed at those sports fans who unequivocally attest that it was as tough in Bradman's day as it is today. Grayson's (the guy at the start of the video) repugnance towards the notion that professional sport will improve playing standards is reminiscent of that shown by fanatical bradmanites towards people such as myself.
A serious response to your post...
If you can show that cricket in the 1920s was purely amateur then everyone will agree with you that it was not comparable to today. Early accounts are that teams from Canada and the USA acquitted themselves well against amateur teams from England for example.
But Hobbs and Hutton at least were "professionals".
In terms of how much cricket they played back then apparently from 1890 onwards each first class team would endeavour to play 16 3 day matches.
It is possible that modern day players play more cricket due to a more jam packed schedule and hence would be better. This would not cause a night and day difference however as a season full of 16 3 day fixtures is still a busy one. Nonetheless this is one argument in favour of Mike.
The other argument in favour of Mike, I must say ..if you are only facing one fast bowler a game and dibbly dobbler stuff from the other end how hard can scoring a century be if the pitch is true and it doesn't rain. I am willing to wager that sticky wickets didn't happen every game. I play on uncovered turf wickets and I have never played on a sticky wicket. I think if dibbly dobblers really were bowling 30% of the overs then this is a knock on 1920s cricket.
Arguments against Mike and company (sorry for singling you out Mike)
Arguments centred around Jesse Owens being slower than Usain Bolt don't seem relevant for a large number of reasons.
1) god knows what Usain Bolt is putting into his body. No doubt it is legal. But he would be crazy if he isn't pushing the envelope of legality because all of his competitors will be. He would lose those advantages/supplements if he went back in time.
2) cricket - especially batting is not a sport based on athleticism. See Jesse Ryder for proof. So even if you could carry your athletic - supplement induced - form back into time I doubt it would help much in cricket.
I reckon the footage is the only legit thing to make comparisons on. And even that has limitations as Marc has pointed out and (analyst1). Some of the shots in that 1950s film looked pretty decent to me. The leggie bowling looked as good as anything you will see today based on his action. I don't think the game would have changed much between 1928 and 1950. So I reckon
some of those shots being played are a point in favour of old time cricket.
The footage of that 1928 test match is too brief. The only thing you can really notice is the bowling.
The clip of that 1901 footage with A N Hornby was not a good advertisement. Hornby if he is the same one on cricinfo somehow managed an average of 24 in first class cricket of the time. Only averaged 3 in test matches which seemed about right.
Lastly Larwood > Michael Mason.