If it is not allowed, then why is it an option to have?
The tags electrical and electricity were already banned back in 2015 because they not useful in the context of this site. Every question asked in this Q&A is about electricity/electronics, so since these tags would apply to everything they are not useful in this context.
Meta discussion was here: The "electrical" tag
The tag has been 'blacklisted', it cannot be applied to new questions... however the moderators cannot finally delete the tag itself as long as there are still old questions that have that tag.
There are still hundreds of old questions that still have these tags. Unfortunately when a question is edited to remove a tag, the question then bumps to the top of the 'active questions' list. Bulk retagging of questions is disruptive to the community, so we try to handle those edits just 3-4 questions at a time, to avoid overwhelming the active questions list.
A lot of those questions also have only the electrical/electricity tag, so in each of those cases a judgement call is required to select a new tag if the question is worth keeping, or vote to close/delete the question if it is not worth keeping. Each of these questions need attention on a case-by-case basis, and with only volunteer effort there is really no timeline for implementation.
I had noticed this recently when doing the retagging for the 'small-electronics' questions that a few of those also had 'electrical', but when I edited such questions the system would not let me submit the edit unless I also removed 'electrical' from the question. So any edits to existing questions tagged 'electrical' require removing that tag, and no new questions with that tag can be created.
Perhaps the tag meta description for electrical / electricity should be edited to say 'do not use this tag'?