Blog - Make Linking in Blog Consistent With Linking in Pages (Site Editor)
When you are linking to a page w/in your Wix site from another page, you can easily pull down/search for the page that is on your site and link to it correctly.
When you are linking to a page w/in your Wix site from the Blog, your options are to link to a section within the post or a web address; pages on site aren't an option). You also need to remember to put in relative link (/page. vs. https://domain/page)? This adds an extra step where you have to have another browser open and go find the exact relative URL on the live site to enter.
While it's understood that the Blog is a separate app from the Site Editor (Blog is accessible directly from dashboard menu), the functionality should be consistent.

Thank you for sharing this idea with us.
In the blog post editor, you are able to link to pages just like other page linking throughout the rest of the web site editor. Make sure you choose "page" when choosing what you are linking to, then you will be presented with all your pages in the drop down.
I hope this helps!