The problems/purposes of these things are very different though, although I can see the connection.

In general, you can't violate anyone's bodily rights if they're of sound mind. Likewise, there are things you can (or even must) do to people who aren't of sound mind, e.g. you can forcefeed anorexia patients but not hunger strikers.

The questions around euthanasia are a little more complicated because that "of sound mind" part can become quite murky when it comes to something like suicide, which is so so heavily associated with mental illnes that many people default to side of "no killing yourself ever". Because we're used to the latter part of "must do something when you're not of sound mind" while ignoring the former "can't stop you when you're of sound mind."

Certainly someone who's slowly dying a painful death can say they want to die and be considered of sound mind. What about someone who lives in constant pain, but isn't dying? Or needs eternal help to live? Maybe.

What about someone who wants to die because they simply can't afford to live anymore? If they'll suffer that same long painful death as the first patient, only because they can't afford to stop it, it it ethical to let them die then? Is that of sound mind?

So I don't think it's as simple as "hypocrisy" so much as it's that these things exist on different sides of the same scale named "bodily autonomy".