It's highly debatable, and arguably a myth. The QWERTY design predated any potential jamming problems. Perhaps it was so foreseeing? It's really hard to believe general ergonomy was the top priority, as all the characters of the word TYPEWRITER are placed in the top row, which could have hardly happened by sheer coincidence, but was very convenient for the sake of sale presentations in the early years...
https://www.smithsonianmag.com/arts-culture/fact-of-fiction-...
Apparently it was partly publicity stunt, partly defined through feedback received from actual users.
Argh, no. E and R are separated by D, 4, and C. It would be nice if someone writing about typewriters actually looked at one.
The bar-adjacent letter pairs, from most to least frequent¹, are MI BY CR NU HN XE HM AZ DC GB ZW VT FV SX.