There already exists quite a popular question asking about the implications of sharing fields between node/entity types:
What's a good balance between reusing fields versus creating new ones in the context of fields scalability?What's a good balance between reusing fields versus creating new ones in the context of fields scalability?
However this only really addresses Drupal 7 and not Drupal 8.
Are there any significant differences in Drupal 8? Are there noticeable performance differences to sharing a lot of fields between node types as opposed to create a new field for each node type?
I know the question should be well defined, but it would also be interesting to know if there are any other considerations to take into account when deciding whether to share/not share fields in Drupal 8.