It’s likely that with Piccolo’s current power, even Majin Buu would fall to him if they came to blows in the Dragon Ball Z, and a character Piccolo wasn’t even considered a threat against. However, that power dynamic has changed since.
In the beginning of Dragon Ball Z, Dragon Ball Super, with Piccolo barely being a factor in their biggest battles. However, Piccolo did get a good fight with Frost in the Universe 6 Saga and he fared well against numerous enemies in the Tournament of Power.
However, Piccolo deserves more credit than he gets. For a long time, Buu has been considered one of the strongest fighters in the Dragon Ball universe, but a character who perhaps deserves more respect than him is Piccolo. Piccolo has lagged behind many of the Z-Warriors for quite a while, but the battles he had in Dragon Ball Super speak volumes about the state of his power. In fact, there’s a very good chance that he could even beat Majin Buu at this point.
First of all, Piccolo easily defeated Super Saiyan 2 Gohan and confirmed that he’s gotten much stronger over the years. Though he had to use a trick, he did prove that he has the strength to hurt Ultimate Gohan, who beat Super Buu when he was at a much weaker power level. In the Tournament of Power, Piccolo and Gohan made an effective tag team against the Universe 6 Namekians. If there is a sizeable power gap between the two, it wasn’t noticeable. Their opponents seemed evenly matched, and Piccolo was certainly able to hold his own, with Gohan struggling just as much as he did. Ultimate Gohan is stronger than him, but the difference between them doesn’t seem to be as huge as originally expected. Also, base form Goku (who is far above Dragon Ball Z’s Buu) itted in Dragon Ball Super that he was barely able to hold up against Piccolo’s Hyper Explosive Demon Wave.
In the manga continuation, it was said that Piccolo has gotten even stronger since the Tournament of Power ended. His training with Gohan has allowed his power to reach new heights. His ability to keep pace with Gohan – Dragon Ball’s third strongest hero – provides strong evidence that Piccolo is finally on his way back to being relevant. It’s hard to say if he could beat Android 17, but it’s become increasingly apparent that Piccolo has sured Dragon Ball Z’s most powerful villain and is now one of the strongest Z-Warriors. Buu, too, has made improvements since those days, but Piccolo’s gains are much more impressive.
