Why are availability reports generated of all items which have trigger?? I'm not sure how many users are well benefited with this reports section in Zabbix but below are few points I would like to highlight if it makes sense and improving it may be beneficial.

Required to have only necessary Availability reports which we can configure as like dashboards.

There is no feasibility to send Availability report via scheduled reports!!

In addition, whatever timeframe I select I'm getting the complete year availability report (see snippet attached).

Better to have:
1. Custom availability reports creation as like we do have for creating dashboards.
2. Time frame selection applies to graph and at bottom should have % for availability and un-availability.
3. able to send report via scheduled reports.