There are plenty of arrows that if Hawkeye adds to his arsenal and bring back others and keep the ones used in their solo show (https://youtu.be/g-HsYLz69to) , not to mention another items, he would be way more menacing like he was in Avengers 1
The collapsible bow: collapsible, with breaks above and below the handle, as well as midway down the length of each limb. This allows the bow to be folded into a more compact form that makes it easier to conceal, carry, store, and transport. When deployed, the bow can swiftly re-assemble in one quick motion as the limbs lock back into place. Four buttons running down the length of the bow’s grip, in line with each of his fingertips, allow Hawkeye to request specialty arrows from his quiver without taking his mind off the battle. Hawkeye can also use these controls to remote trigger certain specialty arrows such as the explosive tip.
Specialized Quiver: Hawkeye's specialized arrow quiver is designed to organize and store his arrows as well as assemble and present them on demand. The quiver is typically worn on Hawkeye’s back allowing him easy access to his arrows. He selects a particular payload via the remote control in his bow's grip and the quiver selects the appropriate arrowhead, and mates it to the shaft of an arrow. The arrow is then lifted up above the other arrows so that it can easily be found and drawn.
Arrow Case: a small cartridge that contains nine collapsable arrows that can expand and be fired at once.
ARROWS-
EMP Detonator: An arrow that releases a burst of electromagnetic energy disabling any electronics within its perimeter.
Burst Shot: A special arrow that contains multiple secondary projectiles. After the arrow hits its target, a ring of secondary projectiles stored in the arrowhead fire in a circular pattern, hitting any nearby enemies. This arrow is useful for attacking groups of enemies. Hawkeye used this arrow to eliminate a group of Chitauri soldiers at once.
Thermal (Incendiary): A special arrow that contains a chemical mixture that can melt through a variety of materials, including most metals, when activated, similar to a powerful thermite reaction. Hawkeye used this arrow to destroy a Chitauri Chariot.
Pulse: An arrow that releases an energy wave at a 360 degree that can incapacitate or kill surrounding enemies, its effects are similar to the Thunderstick. Hawkeye used this arrow when fighting Ulysses Klaue's soldiers to eliminate the remaining soldiers.
Mind-Warping: An arrow that is attached to a small device that delivers an electrical discharge capable of incapacitating a person. Hawkeye used this arrow to stop Scarlet Witch from using her mental manipulations power on him by attaching the arrow to her forehead.
Trap: Two arrows on opposite sides of the area, made to incapacitate anyone who passes between them by using an electric discharge. Hawkeye used this arrow to trap Vision while rescuing Wanda Maximoff from the Avengers Compound.
Flare: An arrow that produces a brilliant light without an explosion, used for either signaling, illumination, or defensive countermeasures. Hawkeye used this arrow to light up a tunnel to see what was behind him when he fell below the surface of the Avengers Compound after Thanos' attack, revealing to be Outriders.
Force Field: An arrow that, when fired, releases multiple small discs at a 360 degree, which create an energy force field inside the area the discs surround. In What If alternate universe, Hawkeye used this arrow to hold off a horde of Ultron Sentries while escaping from the HYDRA Siberian Facility.
Rocket: An arrow that contains a small solid-fueled missile head that is capable of a more powerful blast than an explosive arrow. In What If alternate universe, Hawkeye used this arrow to sacrifice himself, destroying an entire horde of Ultron Sentries.
Pym Particle II (Growing Barrage): creates a swarm of arrows by releasing an entire shrunken volley at once. When fired, the payload is released and expands creating a wide volley of full-sized arrows.
Vibranium
Sleeping gas
Atomic Warhead