Some of this is expected. An instance only knows about the content that it pulled in, and so piefed.ca is missing a lot of stuff from before we spun it up. Similarly, it doesn't start pulling in content from a community until someone from here searches for it. We did a bit of that before we launched, but there are lots of communities that are still not fetched. You may have been the first one to try to access !technology@piefed.social :)
For example, we accessed the main !canada@lemmy.ca community a while back, and so both views are similar (and hopefully identical) by now:
Piefed.ca's feeds should continue to get better over time as more people use it. Lemmy also has a few tricks to improve this process, such as a third party tool that automatically broadcasts new communities so they can be pulled in. Something like that might become available or compatible with Piefed in the future.
It might also be possible to bulk import old posts into piefed, but I'm not sure if that's possible right now. We were able to do something similar with Pixelfed when we spun that up, but we relied on some built in functionality for it.