Summary
The Granolah arc ofDragon Ball Superhad many underlying themes and one of these was the nature of the strongest mortal. Toward the end of the arc, most believed that Gas was the one from the Oracle Fish’s prophecy that spoke about the new strongest mortal in Universe 7, but that belief was quickly shattered when Frieza made his long-awaited return to the series by killing Gas in one hit. Then,he officially revealed his terrifying Black Frieza form.
This form was so powerful that even after Frieza killed Gas, he used this transformation to knock out both Goku and Vegeta, which was even more impressive considering they were in theirultimate forms and using Divine Techniques. Because of this, many have speculated that Frieza has achieved a level of strength that is so great that he can even bring down Beerus himself, so let’s see if this is the case.

Black Frieza’s Abilities Are Like Nothing We’ve Seen Before
Since there hasn’t been much brand-new content forDragon Ballever since the ending of the Granolah arc due to the manga adapting thestory ofDragon Ball Super: Super Hero, the only things to gauge Black Frieza’s strength are the few manga panels that he is featured in. However, these panels still give a very clear indication of the amount of power that he possesses.
The first thing to look at is how he dealt with Gas. Since Gas made a wish to become the strongest mortal in the universe, his body was continuously adapting to surpass thestrength of his oppnents, leading to it becoming a zombified husk of its former self. Gas was heavily damaged due to the collective might of Granolah, Goku and Vegeta but was still kicking and was adapting to get even stronger.

His adaptation put him above all 3 of them to become the strongest in the universe until Frieza came onto Planet Cereal and proceeded to kill him with minimal effort. After transforming and defeating the Saiyans in their ultimate forms, Frieza then went on to make his exit, leading to many fans thinking that this formis on an entirely separate tier of powersince the Saiyans were using Divine Techniques of Gods and Angels.
However, there are some fans of the series who share the opposite opinion about Black Frieza’s feats. This is because although he was able to defeat the strongest mortal in the universe at the time in a single hit, Gas was barely standing due toall the damage his body had sustainedin his battles against the others. And, while his victory over the Saiyans was impressive, many still argue that they too were already tired from fighting Gas.

Beerus is in A League of His Own Among Universe 7 Fighters
By being the God of Destruction of Universe 7, Beerus is the most powerful character in the entire universe, though he is weaker than his Angel attendant Whis. The feats that Beerus has shown ever since his introduction to the series have been second only to the Grand Zeno himself, as the Destroyer’s destructive abilities are enough to allow him to erase entire planets on a whim.
In 2015’sDragon Ball Z: Battle of Gods, one of Beerus’s very first scenes saw him destroying half a planet with a simple tap of his finger and then going on to make short work of every single one of the Z-Fighters on his visit to Earth. This included a greatly empowered Super Saiyan 2 Vegeta, who hadbriefly surpassed even Goku in strength. The end of the film even showed that he wasn’t even trying against Super Saiyan God Goku.

Due to his nature as a Destroyer God, Beerus can use Hakai or Destruction. This is an attack capable of rendering anything to dust, whether it is tangible or not, just so long as what it is being used on is less powerful than the Destroyer themselves. This is the same ability thatBeerus helped Vegeta learn at the start of the Granolah arcand despite its very clear-cut and destructive nature, it is quite versatile in its application.
On top of his powers as a Destroyer, Beerus is also the most formidable ofall the Gods of Destruction from all 12 universes. This was shown in the manga in the prelude to the Tournament of Power where all Destroyers engaged in a Battle Royale to test out the stage. All the Gods decided to start it off by ganging up on Beerus, who was successful in repelling themdue to his skill with Ultra Instinctand overall power until it was just him and Quitela left standing.

Beerus' Destructive Power Gives Him The Advantage… But Frieza Might Have More Potential
At the current moment, this match-up is not a fair one to make due to the lack of screen time Black Frieza has gotten. ForDragon Ball, Beerus is as close to the perfect fighter that the series has shown so far. With his mastery over the destructive powers of a Destroyer andhow adept he is at using Ultra Instinct, Beerus is the only character to have shown significant prowess in both Divine Techniques.
However, even taking Ultra Instinct out of the equation for him,Beerus’s destructive powers are far greater than any abilityshown by a mortal. He is also said to have trained regularly with Whis, though it is unclear if this still happens. More than Ultra Instinct, training with an Angel would be the absolute best training one could possibly get in the entire multiverse ofDragon Ball, so while it was Whis who taught Beerus the Angelic technique, this training is most likely what made Beerus’s own destructive powers so terrifying as well.

The biggest thing going in Frieza’s favor is the ease with which he took out the 3 strongest mortals in the universe. Though the argument about them all being tired at that point in the story remains, it is an incredible feat nonetheless, ashis strength and speed surpassed anythinghis opponents could react to. Frieza’s greatest advantage going into a potential battle between the two is his potential, as 4 months' worth of training got him toSuper Saiyan Blue level, and 10 years worth of it made him toy with Goku and Vegeta like mere children. So, it would be very interesting to see how Frieza with far more time to train would match up to the Destroyer!