^^^
Definitely, the playing schedule is much heavier now, and you need to balance which matches you play if you are focusing on every format. There used to be a strict break during the rainy season. Teams would either tour overseas during that period or take a proper break. Now, there is a schedule round the clock.

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These guys are legends no doubt but they are somehow jealous as well, because they never got the recognition since they played in a different era. So by ridiculing the rest theory, they are basically telling how hard-working they were in their time.
All of the legendary players had massive name recognition and immense popularity among cricket fans around the world. In the social media era, it is completely different; older legends might not be as active online simply because they didn't grow up with these platforms. They ones that are active might be doing with social media management teams.
It is true that perhaps too much focus has shifted from abilities to fitness. Sachin was never the fittest, and with all due respect to him, he might fail the now-popularized Yo-Yo test, and in fact most legends would, even in their prime. Cricket isn't UFC where you need 6-pack abs and 16' biceps to play the game. Take Chris Gayle, for example; he's the best T20 batter but perhaps won't pass any of these fitness tests.
In the past, the Australians were built differently. They were the ones who truly took fitness seriously in the 90s, followed closely by South Africa. Sachin Tendulkar took his fitness seriously after his injuries in the late 90s, if not it is impossible to play 24 years of international cricket.
Cricket, I feel, is heavily influenced by glamour and because most cricketers get ads and brand endorsements, they have to be good-looking and muscular rather than being suited to the skills required to play the actual game.
As long as Cricket is the most popular sport in India, so it is natural to see players getting brand endorsements. This massive commercial boom was truly accelerated by Sachin Tendulkar. While players in the 80s and before played mostly for passion and glory, commercials began giving them a real income. Today, the landscape has shifted completely, and nearly every top player is a millionaire.