There is no clear-cut answer when it comes to whether or not travel blogging can be considered travel writing. After all, what separates a travel blog from a personal blog about your travels is the level of detail and the level of engagement with readers.
If you are documenting your travels in a way that engages readers and provides them with insights and tips on how to make the most of their own trips, then you are writing travel writing. If you are simply posting photos and snippets about your travels without providing much context or commentary, then your blog may not be considered travel writing.
Ultimately, it is up to the reader to decide whether or not they consider your blog to be travel writing. If you engage with readers and provide them with valuable information and tips, then you have created a worthwhile travel blog that can be considered travel writing.