If you recall back when Goku first unlocked Ultra Instinct Omen and then proceeded to master Ultra Instinct within 45 minutes, it surprised all the other Gods of Destruction and managed to place the biggest smile on Beerus’s face
To think that Goku, a mere mortal managed to master a skill that the Gods had not yet been able to, is worthy of respect. And it signaled to Beerus that the premonition he had years ago about a strong and worthy opponent was true.
However, this is not to say that Beerus has never managed to tap into the power himself.
Beerus actually does show off Ultra Instinct Omen before Goku ever does. In the tournament of power arc, the other Gods of Destruction all jump Beerus at the same time when they’re pissed at the fact that someone from his universe aka Goku, started the tournament.
This was meant to foreshadow what Ultra Instinct is capable of, long before Goku manages to achieve the power.
We’ve also been told by other characters that although Beerus hasn’t managed to exactly master it the way Goku has, he is still the only God who has successfully learnt the skill. We see this demonstrated when no other God of Destruction could muster up the same power to fight Beerus.
There’s still a lot to his power we have yet to see, he only used 70% of it reportedly in the Battle of Gods movie after all.