Emulator Issues #12035
[macOS/Qt: “qt.qpa.fonts: Populating font family aliases took 419 ms. Replace uses of missing font family "Monospace" with one that exists to avoid this cost.“
When running Dolphin from the terminal, Qt always outputs the above mentioned warning. Dolphin seems to have the “Monospace” font (the one by George Williams, which ships with most Linux distros) hard-coded at some place. However, AFAIK neither macOS nor Windows ship with that particular font, hence the half-second delay while Qt figures out how to sensibly replace it on launch.
This might be fixable in a similar fashion as PR 8632 (“Windows GUI: Use QMenu font (Segoe UI) for entire application”).