Goku is one of the strongest characters in Dragon Ball, and he is capable of defeating anyone. But Dragon Ball’s theme is that there is always someone better. This concept is always followed by Dragon Ball.
CHARACTERS GOKU CAN’T BEAT YET
CAN’T BEAT BROLY
It can be seen that Goku and Vegeta had to fuse into Gogeta to turn against Broly, which signifies that Goku alone cannot defeat Broly. It also reveals that Broly is stronger than Beerus, Goku’s former opponent.
NOT YET ZENO
It really seems that Zeno will stay the strongest god in Dragon Ball for the foreseeable future. His level of power is so unbearable that it seems that Goku will ever beat Zeno if he is let alone to fight him.
NOT WITH JIREN
A character like Jiren is, a thoughtful thematic foil for Goku, he is fundamentally and philosophically opposite Goku. Jiren has a raw power that Goku lacks, but he lacks passion, which Goku has for martial arts and self-improvement. Maybe in the future, Goku will surpass Jiren. But not yet.
NEVER WILL: WHIS
It is recently established that angels cannot interface with mortal arts. Goku will never defeat Whis. This is so far above Goku.
CAN’T BEAT MERUS
We cannot see Merus fight again. Merus is a highly animated character; Goku cannot fight easily with him until he becomes stronger.
NOT WITH ANGELS
It can be seen that none of the angels can be defeated easily because they are designed to be unbeatable. And also, Goku can never beat Beerus. Beerus is highly powerful in all senses.
NOT WITH MORO
It is also unlikely that Goku will go head to head with Moro. There are no chances that Goku will beat Moro ever.