I started out in Buddhism with Zen Buddhism. I think it has a lot to offer. But at the same time one should think about what it doesn’t offer. One should weigh the pros and cons.
One of the interesting developments in Mahayana Buddhism (of which Zen is a part of) is that of the Bodhisattva and its (it is both a he and she. And it is a non-existent person) ideal. A bodhisattva is said to strive to save all beings before its leaves this world into Nirvana, the final extinction.
In contrast the Theravada has the Arhat ideal. An Arhat is anyone who has vowed to become enlightened, the highest ideal that leads to contentment. Mahayana sees the Arhat ideal as selfish which is why they developed the Bodhisattva ideal. This was a later development after the Buddha’s time.
So if you ask me which is “correct” I will say both.
I doubt The Buddha meant for his teaching to be selfish (the supposed Arhat ideal interpretation) in any way. But neither did he mean for it to be an active and engaging teaching (the Bodhisattava interpretation) either.