It was a business decision: Jason Statham reportedly left Hobbs & Shaw after cutting connections with a $315m franchise for underpaying Dwayne Johnson

In 2002, Jason Statham made his debut as a true action star when he played the mysterious driver and action hero Frank Martin in the film The Transporter. Throughout his career, he has produced many noteworthy movies, but the enduring Transporter series is the one that sticks out in his discography.
But Statham passed on The Transporter 4 after starring in three Transporter films as the most fierce courier ever. And he has a legitimate explanation for it.

An offer was made for Jason Statham to star in The Transporter: Refueled. However, he has already made the decision to sever connections with the $315 million franchise and decline to reprise the part.Fast and Furious 7' Spoilers: New Photo of Jason Statham Released; Is he the Perfect Villain? - IBTimes India  
“What dо yоu knоw? Making thоse videоs was clearly a terrific experience, and I wоuld have lоved tо cоntinue. Hоwever, they оffered me less mоney tо dо three films than I wоuld get paid fоr оne, and they wanted me tо sign оn tо dо three mоre withоut even hearing a script! Statham stated in an interview with Vulture.

Therefore, it was a business choice. Although I would have loved to, you can’t actually sign on without performing a script, and for three of them? And for such meager pay? I simply didn’t understand the point of that.Fast & Furious Presents: Hobbs & Shaw (2019) 

In 2015, Ed Skrein took over as the director of The Transporter Refueled when he declined to return as Frank Martin. See Also: Dwayne Johnson Responds to Criticism Regarding the Maui Wildfire Fund, Saying, “I’ll be better next time,” and Describes How His Team Used the Donated Money
 Fast & Furious Presents: Hobbs & Shaw, a spin-off film starring Jason Statham as Deckard Shaw and Dwayne “The Rock” Johnson as Luke Hobbs, is one of the most notable additions to the Fast & Furious world.Hobbs & Shaw 2 Is Officially Happening According to Dwayne Johnson 

Unquestionably, one of the main elements in Hobbs & Shaw is the chemistry that exists between Dwayne Johnson and Jason Statham. Subsequently, word spread that they would target Hobbs and Shaw 2. However, Statham gave it up and joined the blockbuster Fast & Furious franchise.

It has been reported that Dwayne Johnson and Jason Momoa will co-star in the Hobbs spinoff. Momoa was meant to be in Hobbs and Shaw as Mateo. But he was not able to because of his hectic schedule.

When a fan inquired about Jason Momoa and his absence on Instagram, Dwayne Johnson responded in the post’s comments:

Yes, Jason Momoa and I worked very hard to convince him to play my brother in this film, but his schedule was too full. Hobbs’ next film, for sure.

According to Hiram Garcia of Seven Bucks Productions, Hobbs & Shaw 2 is currently being developed, as reported by TheWrap: “We are writing the story, so we never like to announce anything like that too soon.”