There’s also the fact that wikis are used to store information that can be edited at a later time by a third party, which is something that blogs cannot do.
Perhaps this is a part of where the definition changes for me to blur the difference between the two modalities (wikis vs. blogs). If a wiki is held as public, yet still personal and any changes to it are done by a fork and edit by a third party with a webmention back to the original, then the barrier can be removed. If one can use a webmention notification from the branch back to the original so that the new knowledge can either be aggregated or not at the first party's discretion. This allows the ideas and potentially growing voice of atomicules of information to grow and spread.
This gives a bit of the best of the both worlds. There can be multiple minds and models working, but the information can still be shared and aggregated over time. This may also expand creativity as there isn't necessarily one canonical source, but many.
Thus a personal wiki and blog combination can use small atoms of information in a wiki-like style to slowly build up a set of facts where a longer blog-like article then becomes a crystallization of a specific voice's synthesis and analysis of those underlying facts.
If the wiki chunks are copyable and sharable then different people may synthesize different ideas. Additionally by reshuffling the various pieces, the author of a particular blog article may rewrite or revise their original thinking with additional smaller wiki-like pieces to come to an alternate or expanded conclusion.
Thinking of a wiki as something that has to be voiceless and communal may be the biggest wall between the two modalities. If there were a larger community of personal wikis that were interlinked then these barriers might be broken down.
Additionally, this is more like what the OER community may be looking for. There are very concrete topics like calculus, as an example, but there can certainly be dozens of approaches to the topic in as many or more voices to suit the needs of particular learners. In fact there are many calculus textbooks geared toward different audiences: biologists, physicists, economists, mathematicians, social sciences, etc. The underlying ideas may all be incredibly similar but could be remixed in different and creative ways.