WARNING: The following article contains spoilers for Dragon Ball Super Chapter 77, "Bardock, Father of Goku," by Akira Toriyama, Toyotarou, Caleb Cook and Brandon Bovia, available now in English through Viz Media.
The Heeter family is the latest in Dragon Ball Super's line of villains vying for absolute power. They believe that if they can take Frieza out of the picture, their business will be unrestricted and they can take over the cosmos. This seems like sound logic, but there's a major flaw: Frieza has already been dead.
If the Heeters were really capable of taking control of the universe from the Frieza Force, they could have done so when their leader actually was out of the picture. Despite this, they seem confident that their current plans are what will cement their place at the top. Understanding the Heeters' line of thinking will require a deeper look into who they are and what their plans are.
The Heeters apparently have a history in the world of Dragon Ball predating the series itself. They are the brokers who handle the selling of planets conquered by the Frieza Force. They represent the business side of Frieza's operation that is only ever alluded to in Dragon Ball Z.
Since the Heeters work under Frieza, they are naturally dissatisfied with the unequal conditions of their partnership. Unfortunately, Frieza's overwhelming power and influence make him difficult to oppose. If the Heeters want to usurp him, they have to be smart and play the long game.
What's really interesting about the Heeters' waiting game is that they already have someone they believe is strong enough to fight Frieza. One of the siblings, Gas, is presumed by their leader Elec to have the potential to surpass Frieza. He is also believed to be strong enough to take on Granolah, the current strongest mortal in the universe. If Gas is that powerful, it seems like the Heeters should have been able to seize control of the universe from the Frieza Force a long time ago.
It's difficult to say just how powerful Gas really is. As of Chapter 77 of the manga, he has yet to be seen in a serious fight. The only real fight he's shown in is one with Bardock from 40 years ago. Even if the results of the fight were revealed, they would be heavily dated and thus irrelevant in gauging Gas' current strength.
It's also unknown whether the Heeters can actually overcome Frieza. Even in the current arc, Elec only believes that Gas has the potential to win a fight against the galactic tyrant. It doesn't help that Frieza has died and come back stronger than ever two or three times throughout Dragon Ball. If the Heeters want to take over, they'll have to make absolutely certain that Frieza will not be able to stop them.
Part of why the Heeters are only now acting may have to do with Elec's master plan. He may be confident in Gas' abilities, but he believes there's more to acquiring power than brute force. Elec puts particular value on the power of information, more so than military strength. In accordance with this belief, Elec's plan apparently involves finding the all-knowing Zuno, the greatest source of information in the universe. Since Zuno's location is a recent discovery for the Heeters, it's only now that they can finally continue on to the next step.
A recent addition to Elec's plan is the use of the Dragon Balls. After seeing Granolah successfully use the Dragon Balls to gain immense power, Elec is convinced that he can use them to help in his conquest of the Universe. Even with Gas on his side, Elec wants to use the Dragon Balls as a form of "insurance." Gathering the Dragon Balls may become a setback in the Heeters' schedule, but they'll do it if it can assure them victory.
The Heeters intend to dethrone Frieza and take over the universe, but only when they can secure their position. They must rely on their latest accomplishments to give them both the power and the information they need to guarantee that nobody can stand in their way. Until then, they intend to steadily approach their goal with caution and patience. They've already held out for at least 40 years, so a little more waiting shouldn't hurt them.