The dash is not part of people's keyboard. But the weird hyphen/minus character is (I mean ideally we would use minus for minus and hyphen for hyphen but that is just how it is).
Most people do not know about typography.
It's not terribly wrong in the general audience's opinion either. So saying it is incorrect is slightly stretching things ...
There's a lot of theory about soap as well, but most people find out about washing hands in case of a global medical emergency — most people have no idea what dashes are and Youtube does not employ designers/typographers to fix names and descriptions in whatever is being uploaded — it is mass content and it is, what it is.
I grew up in the heyday of peer-to-peer file sharing, and I first heard a lot of the bands I love now through mp3s shared by friends, pen pals, and generous strangers. Wherever they came from, most of those mp3s were labeled in the “artist - song” format, and if they weren’t I changed them to match. I think a lot of people did the same.
I can think of a few ...
Constructs intended for machine-processing should generally use ASCII characters when practical. If a name is rendered using non-ASCII characters, it may get transformed to something else when a file is moved between systems, foiling efforts to e.g. take a list of files and import it into a table. Using consistent ASCII characters avoids such issues.
Stock art almost always comes with the text converted to outlines. You can edit it as a regular vector shape by manipulating anchor points, but it is no longer editable as live text. Instead, you have to completely replace it with new text elements of your own. It might seem counter-intuitive for a company to offer text-based stock art with no live text, but ...
Standard usage changes with technology. Since typesetters and editors are no longer the hate keepers of published text, I am sure the ‘proper’ use of en/em dashes will change. I mean, who really cares about correct hyphenation any more? Who really knows how to hyphenate manually? A very select few.
First of all Justify all lines might not be the best choice. When you force all lines to be justified the last line will often look bad. It's a coincidence if your text will look good, not all texts can be layout like this simply because of the number of letters.
Instead you should try using Justify with last line aligned left and accept that the last line ...
Definitely. You need to set up two separate styles:
one style for simple text (not numbered)
a copy of that style where you merely select 'Numbers' under 'Bullets and Numbering' section of this second paragraph style. the auto-numbering will work with everything else set by default under this panel
further read: https://helpx.adobe.com/indesign/using/...
Justify will never work with a text column so narrow.
There is nothing you can do in the settings to make that specific setup work. Instead, use left align, or change the design so that text box is much wider if you really need to justify.