Cricket Became a professional sport, and IPL is the biggest league of this game
In 1975, the Indian Cricket Board used to pay a fee of 2500 rupees to the players of Team India to play a Test match. Then came ODI cricket and in 1983 we became champions in the third World Cup. You will be surprised to know that when our players came back to India after becoming champions, BCCI did not have money to give to its players. Then Lata Mangeshkar did a show for the team and the money that came was given to the players.
Earnings increased after the 1983 World Cup, but even then the BCCI had to pay a fee of Rs 5 lakh to Doordarshan to show a match of India on TV. Barring Australia and England, almost all the cricket boards around the world had a similar situation.

Cricket became a professional sport, and IPL is the biggest league of this game
Successful sports in the Modern Era are those who have made their mark at the professional level. The biggest condition for success at the professional level is the existence of a franchise league.
Sports like football, basketball, ice hockey, and baseball fulfill this condition. With the advent of T20, this became possible in cricket as well. A T20 match is completed within 3 to 4 hours and the intensity remains constant. There is no moment of boredom.
Access of cricket to more countries
The popularity of the T20 format has increased the reach of this game. The first test match was played in 1877. Even after 145 years of its inception, so far only 12 countries have been able to play in this format. The scope expanded a bit from ODIs, but T20 revolutionized itself.
The shorter the format in cricket, the greater the chances of a turnaround. In a game of 20-20 overs, even the weaker teams are expected to win. Therefore, this format was adopted by many countries in a very short time.