Logging to Systemd journal by default?

This might not be the right place to start this discussion, please let me know if it's not.

I've seen a couple of bug reports where people where asked to restart the application with debugging enabled (`-d`):
- https://github.com/elementary/applications-menu/issues/52
- https://github.com/elementary/appcenter/issues/602

This is problematic because issues aren't always easy to reproduce. I understand some services leave logs in systemd's journal. I can for example request redshifts logs using:
```
journalctl -u redshift
```
Why don't the parts that make up elementary OS log to this journal? Would this impact performance? It might take up more disk space, although that's limited by configuration. Looks like it only keeps 100 system and 100 runtime log files.

Now why I'm opening this here, I noticed that Granite has a logger service (which is even automatically initialized in Granite.Application). Wouldn't it make sense to have this logger log to systemd journal by default?