How can I change which view wins over two using the same path? I have two views in Drupal 8.

The standard Taxonomy term (content) view, path: /taxonomy/term/%
My custom view for just one term at path: /term-alias

When I go to my custom term, I see the view for all terms (#1), when I want to force it to #2.  How can I do that?
Use the internal path of the term:
/taxonomy/term/123

Route matching operates only on internal (unaliased) paths and route #2 having more fixed parts wins.
See https://api.drupal.org/api/drupal/core%21lib%21Drupal%21Core%21Routing%21RouteCompiler.php/function/RouteCompiler%3A%3AgetFit/9.0.x