One of the rug pulls that Marvel got over on fans with The Thunderbolts* was the fate of Taskmaster. Olga Kurylenko's character was billed as an equal member of the antihero team early on, except she met an untimely demise.

What's even more surprising is how quickly Ghost (Hannah John-Kamen) ended Taskmaster's life. During a brief fight sequence, Ghost simply vanished and reappeared in front of the former Russian assassin before pulling the trigger of her seemingly normal pistol.
The striking thing is that despite all of Taskmaster's training—the combat mirroring—all the preparations she made—these skills made little difference in a fight with Ghost. It's conceivable that Taskmaster's abilities were toned down for this particular movie since various instances from 2019's Black Widow demonstrated her ability to dodge and redirect projectiles with nearly impossible counters. Moreover, witnessing her fall to a single bullet after feels odd.
In all likelihood, Marvel intended to kill off that version of Taskmaster from the beginning. The character plays a significant role in events involving the Avengers, the Masters of Evil, and virtually every team of heroes, making her existence vital to the storyline.
It's worth noting that Taskmaster played a small role in the Ant-Man and The Wasp prelude. In that narrative, the Avengers seemingly team up with Hank Pym (Michael Douglas) and Janet Van Dyne (Michelle Pfeiffer) to take on the villainous Taskmaster—something that never happened on the big screen. Perhaps a movie based on the Silver Age Avengers was once on the table.
Considering the number of Silver Age characters that the MCU has gradually sprinkled throughout the live-action universe, it's reasonable to conclude that Marvel Studios is planning on developing a classic-style Avengers movie. There's Hank Pym and Janet Van Dyne—the original Ant-Man and Wasp to consider. The universe also contained Bill Foster (Laurence Fishburne) back in the 70s. King T'Chaka—while not active in the MCU—received a faithful introduction to the world in an episode of Marvel's What If. And finally, Howard Stark could round out the team.
While not a wholly faithful representation of the Avengers, it's the closest thing to an old-school team that viewers are likely to see. And Taskmaster is a classic villain with ties to both the past and current MCU narrative. Together, those are all the elements that one needs to make an entertaining film.

Keep in mind that the question of why Taskmaster was so easily defeated remains. Maybe the character will receive a proper sendoff in a movie set during the 60s or 70s. Of course, that may not be until further down the line because Marvel has a full slate of movies to develop before adding more to it.
*The New Avengers is currently in theaters everywhere.