if I go to the Artifacts tab in blue ocean, I can see the artifacts.
However, for each artifact I can only download the artifact.
On the legacy UI, there was a link to view the artifact as well.
For example https://myjenkins/jobname/29/artifact/somefile.txt will download the artifact
will view it in the browser.
I use that feature a lot because I archive certain log files during test runs which are handy to view in the browser.