Your questions as I understand them:
- Is duplicate content a problem?
This has been extensively discussed by Google (going back to 2008). Here is a quote from Susan Moska from the Google Webmaster blog:
"Let’s put this to bed once and for all, folks: There’s no such thing as a “duplicate content penalty.” At least, not in the way most people mean when they say that."
Here is the link: https://webmasters.googleblog.com/2008/09/demystifying-duplicate-content-penalty.html?m=1
If you are concerned that this information is outdated, here is a more recent article from SearchEngineLand that discusses this very issue (the conclusion is the same as above, I am linking it in case you want to read further): https://searchengineland.com/myth-duplicate-content-penalty-259657
- How unique does content have to be?
This is difficult to answer. Fundamentally, remember that Google strives to add value to users. As long as "you are helping someone answer a question" you are ok. A good way of thinking about this is Rand Fiskin's concept of Pogo Sticking (worth googling if you aren't already familiar with it). Assuming you are already familiar with his work on this topic, you can use this concept to sanity check your content "will a user pogo stick if they click on this?" As long as the answer is "no", then you are satisfying the first criteria of helping a user answer a question.
To look at this from a different angle, you can look at automated content generator tools (contracts for these are typically in the tens of thousands of dollars) like Quill (used by Forbes), and Wordsmith (used by the Associated Press). These tools help these news outlets generate thousands of articles on things like quarterly reports and minor league baseball commentary automatically.
Relevant to your situation, an aspect of Wordsmith is its use of if/then statements to programmatically create content as dictated by the state of different variables.
Here is an article from Search Engine Journal that explores this from back in 2018:
https://www.searchenginejournal.com/ai-vs-human-seo-content/268629/
Tldr:
duplicate content will not penalise you. This is a widely perpetuated myth (much like eating carrots will improve your eyesight).
Are your articles answering a question? If yes, then they should exist.
Finally, there's a lot of commentary in the answers to your question on creating unique content. I think it is useful to remember, there are many pieces of content that are not unique in nature, and are very easy to generate programmatically, that are very useful to users. Examples include: summaries of quarterly financial performance, opening hours, distances to major landmarks and tourist attractions, products and brands sold by a given store location, conditions treated by a given doctor's practice, and so on.
I hope that this helps.
**Sorry for formatting. On mobile.