I think it's beneficial for every Buddhist to understand what the Buddha himself taught. I don't see how it's possible to make an educated decision on which practices to follow without a solid grasp on where it all comes from. Because no lineage represents the Buddha's teachings perfectly. A whole lineage is just too wide a scope for that to be possible. In every lineage there are countless sub-branches. Some are more in line with the Buddha's original teachings, some less so.

There are early Buddhist texts and later Buddhist texts. Early texts include the Pali suttas and Chinese agamas. Late texts include things like the Visuddhimagga or Lotus Sutra. Not all later texts conflict the Buddha's original teachings. And not all early texts are authentic. But through linguistic and parallel analysis, we can accurately extract the core of the Buddha's teaching from early Buddhist texts.

If you want to explore this further, I recommend "In the Buddha's Words" by Bhikkhu Bodhi. It's also worth looking into lecture series from Bhikkhu Bodhi, Ajahn Brahmali, Bhante Sujato.