that "reader" is just less.

No mention of using the reader is in the man page for journalctl.

err, said man page:

The output is paged through `less` by default,

but:

but G does not go to the end of the file. In fact, if press G, the stream freezes and I have forcibly terminate it.

G works beautifully, the log is just very long, so it's searching for a long time until it reaches the end.

from the man page:

  -e, --pager-end
      Immediately jump to the end of the journal inside the implied pager tool. This implies -n1000 to guarantee that the pager will not buffer logs of unbounded size. This may be overridden with an explicit -n with some other numeric value, while -nall will disable this
       cap. Note that this option is only supported for the less(1) pager.

So,

journalctl -e

is what you want to run!

that "reader" is just less.

No mention of using the reader is in the man page for journalctl.

err, said man page:

The output is paged through `less` by default,

but:

but G does not go to the end of the file. In fact, if press G, the stream freezes and I have forcibly terminate it.

G works beautifully, the log is just very long, so it's searching for a long time until it reaches the end.

from the man page:

  -e, --pager-end
      Immediately jump to the end of the journal inside the implied pager 
      tool. This implies -n1000 to guarantee that the pager will not buffer 
      logs of unbounded size. This may be overridden with an explicit -n 
      with some other numeric value, while -nall will disable this cap.  
      Note that this option is only supported for the less(1) pager.

So,

journalctl -e

is what you want to run!