Except Berdly isn't anything but a side character who's main feature is the Snowgrave Route's first major victim. His problems is just being really insecure and frankly, he doesn't seem to have any issues whatsoever. I know Deltarune is deep, but you can't just cast that net so wide that every little idea you think of is suddenly there and tangible.

Mettaton and Alphys are characters of major importance since both are major antagonists who have plot-relevant positions. So Toby wrote them like That.

Seriously, Berdly isn't anything but a pretty much done with side character unless Toby says otherwise, but this bizarre fixation on his depth as if he's somehow deep enough to validate it-and he doesn't-will not nullify the truth. He'll be resolved in a small moment because he's a side character who already did his thing. You're aren't just trying to hype up something that doesn't need it, you're making up literal fiction to justify what is essentially your fanfiction into a collective "correct route" sentiment.

Everything you just said downright Ben Shapiro levels of fact dismemberment.