Evidence of Pali Canon's Origin Are the Buddha's words the source of the Pali Canon? What evidence is there of the Pali Canon's origin? What do scholars say?
I encourage you to read the following: Bhikkhu Sujato &amp; Bhikkhu Brahmali. The Authenticity of the Early Buddhist Texts.
In this work, their project is to investigate the question of authencity systematically. In that, the approach is quiet academic and might be to your liking.
Page 7, they state a feature of the early Buddhist texts:

The Buddha’s presence as a living figure in the EBTs is overwhelming
and unmistakable. It stands in stark contrast with all other Buddhist
literature, where the Buddha has faded to legend.


Page 8, they assert that, although they accord with the meaning of Buddha Dharma...
> We are not denying the obvious fact that the texts bear all the marks
> of redaction and editing, and that they have been optimised for the
> oral tradition.

Page 151, they state what we owe to the early Buddhist texts:
> We know when the Buddha lived, where he lived, who he associated with,
> how he lived, and what he taught. We know these things with greater
> certainty than for almost any other historical figure from a
> comparable period. And we know this because of the EBTs. All other
> historical and archaeological information about the period depends on
> the EBTs to make sense.
Their overall conclusion is that although the Pali canon &quot;bears the marks of redaction and editing&quot;, the meaning accord with the intent of the Buddha. Bhikkhu Sujato and Bhikkhu Brahmali expose various argument (sorted out by chapters, that all constitute different angles: geographical, historical, and so forth) in order to highlight the proximity between what is written in the Pali canon and what the Buddha [presumably] said.