i don't know if test cricket was ever in 50 year slump - maybe a 10 year slump around and after World Series Cricket - and only a maybe... but true, if Australia of the 90s hadn't come along a slump may have prolonged...
And there is nothing wrong with subcontinent pitches... they are just different. What was wrong with the standard of cricket just seen between Pak and Eng?. And what about Ind vs Aus in 2001 and 2004? - or SL vs WI (BC Lara more like it that series) in 2001- that 2001 Ind vs Aus series remains the best, most exciting cricket i have ever seen - slightly ahead of the 2005 Ashes. And if it wasn't for a washed out 5th day in Chennai for the 3rd test in 2004 Ind vs Aus series, Australia still probably wouldn't have won a series in India for 30+ years!
I will correct myself, not a 50-year slump but a 70-year slump.
There are, of course, highlights inside a long term slump and yes the windies in the 80´s were no doubt such a highlight as they went non-stop for the batsmens´ heads with their 4 pace men and no spinner. But to me that just proves how low cricket had sunk that you had to play like that to unsettle the batsmen. Their tactics are actually illegal today so it was hardly all that great, but they unsettled the batsmen and that it was cricket has needed for so long.
You need wickets and a bat-ball balance that forces batters to go for runs because if they just block all the time they will eventually get out, better make some runs first. when you have that then both ball and bat have to attack when overs arent limited. That balance disappeared a long time ago but has come back.
For almost 70 years batters have basically set out trying to bat for some 200 overs to get a big total as slowly as possible in order to secure a draw with a shot at winning. had tests been expanded to 6-7-8 days it would probably had become even slower, because batsmen were in control.
After England had scored more than 900 runs in their first innings at the oval in 1938 (and actually declared in a timeless match, presumably in order not to bore themselves to death) Bradman wrote as an opinion to the question of lengthening matches that its about pitches not days. Matches should essentially be played in timeless sense but would with the right conditions always finish inside 3-4 days.
He wrote that in 1938 but I would say it never really came about until the 1990´s as a result of batters improving their capabilities to score run ( through ODI-cricket) meaning the run rate increased considerably while they were still likely to get out on proper pitches. this changed the logic. better score some runs before you get out.
The last ashes were fought with that timeless approach. the entire ashes run rate was above 4, double that from the 60´s while the duration of matches fell considerably. there were no wars of attrition with 200+ over declared innings. day 5 was essentially a reserve day for bad weather. Both teams attacked because they thought it was the best way to get the most runs. Thats how cricket should be played and was originally always played.
100 years ago all cricket was timeless, even english school games were timeless. It was as natural as not having a time limit on tennis matches.
(county cricket did have a 3-day limit for practical reasons but really only the weather would cause draws)
Limitting the overs would have been considered insanity then as it would appear obvious that this would make the game defensive. That logic will come back if the ashes were a sign of cricket in the future. ODIs cannot live alongside that kind of game.