What there is a 4th one in the works?
Honestly, there are plenty of other Marvel properties that could be made instead of revisiting Spidey.
Part 3 was flawed. The multiple enemies in the movie reeks of the later(earlier) Batman movies, Although Batman Returns pulled it off (thank Tim Burton), the rest became progressively worse and worse.
Venom is too major of a villain to be dispatched of in one movie. He is too major of a villain to play second fiddle to another.His treatment in Pt 3 is reminiscent of how they used Bane in that Batman movie(suppressing which one at the moment). He played 3rd fiddle to Mr Freeze and Poison Ivy, and he is gone as soon as he appears...Bane took Batman out of action for good while in the comics.
Part 3 should have been about Spidey getting the alien symbiote, and the major/only villain should have been Sandman. At the end of the movie he gets rid of the symbiote and Venom is foreshadowed for the next movie.