Jonathan, there could be multiple reasons of page loading slow.
1) PHP version less than 7.1
2) Cache not enabled
3) Cache is created on page load and not by cron job.
4) You are using an older version of sellacious
5) you are using an older version of Joomla
6) Your WebHost is using conventional Apache server. We recommend Nginx or Lightspeed servers (the best and fastest)
7) Your WebHost is using HDD to host and not Fast SSD
8) If you are using shared hosting, your websites is crowding it and not allowing sellacious to consume bare minimum resources.
9) Your host has not enabled CLI.
10) The network bandwidth bottlenecks on either host side or client-side.
Please check these, if you cross-check your website against these points, you can easily achieve sub-2.7-sec page loads using sellacious.
You can also ask us for our cloud-hosted plans which are blazingly fast as we use best infrastructures, lightspeed servers and tweaks settings for faster sellacious load speeds.
-Abhishek
Team sellacious.