I think they've been fully converged in most strong practitioners for a long time.

There's a specific type of "data engineer" (quotes to indicate this is what they're called by the business, not to contest their legitimacy) that just writes lots of SQL, but they're usually a bad hire for businesses. They're approximately as expensive as what people call platform engineers, but platform engineers in the data space can usually do modelling as well.

When organizations split teams up by the most SWE-type DEs and the pure SQL ones, the latter all jockey to join the former team which causes a lot of drama too.