A Will Smith Deadshot solo film starring Will Smith was once in development. The film, however, was reportedly put on hold due to Smith's $20 million salary requirement.
Will Smith played Floy Lawton, the mercenary known as Deadshot, in 2016's The Suicide Squad, but couldn’t be in the movie due to schedule conflicts.
Will Smith's Deadshot movie not happening makes sense when considering that the DCEU has effectively replaced the character. As Suicide Squad franchise besides Harley Quinn were to receive their own movie, then it would make more sense to be the characters from the much more well-received The Suicide Squad.
It's also worth noting that Will Smith's Deadshot is closely tied to Ben Affleck's Batman. It’s Affleck’s Batman who Smith’s Deadshot goes up against at the beginning of Suicide Squad, and it’s the Batman v Superman: Dawn of Justice’s version of the hero who arrests Floyd Lawton. However, Ben Affleck's status as Batman in the DCEU is still quite uncertain, with the actor having already stated he no longer has an interest in working with IPs. If Ben Affleck's Batman and his universe don't continue in the DCEU after The Flash, then it would make even less sense for a movie focused on one of his villains to be made. The Suicide Squad characters like Bloodsport and Peacemaker, on the other hand, are not tied to any specific version of a DCEU hero and may have a much more consistent future in this new phase of the franchise.
There's no doubt that Will Smith could carry a Deadshot solo movie, but it's good for the DCEU that the project never went ahead. Aside from the financial matter, a Deadshot movie would also be a risky gamble in of audience reception, and it could have suffered the same kind of rejection that Birds of Prey and even the well-received The Suicide Squad suffered because of the first Suicide Squad. The 2016 movie shouldn't be something the DCEU wants to revisit, and the franchise should instead look to the future.