There are add-ons that have prerequisites not included with the standard Gramps installs. Their prerequisites must be manually installed before the Add-on registration can be successful.
The Prerequisites Checker add-on is a useful Dashboard gramplet to explore.
Some (like PyGoocanvas for Graph View and pygraphviz for Network Chart) are generally useful but add quite a bit of overhead. So you need to be aware that you are adding complexity to your Gramps installation.
Refer to this thread for lead on resolving those particular error messages on a Linux (Ubuntu) system:
Some (like PostgreSQL) are add-ons that are used rarely and for specific objectives. Don’t worry about those add-ons unless you identify a need to install those particular tools.