You can use tor also for search, reading articles, and research topics that you don't want associated in any way with your traceable internet persona (no region, ip, etc) identifiers / telemetry.

There are lots of reasons to use tor that have nothing to do with illegal sites.

Anything that you want to really keep private and never creep back into your normal day-to-day browsing experience (considering divorce, medical conditions, future vacation plans, "taboo political ideologies", etc.).

Traveling to a foreign country with questionable privacy laws?

You can access normal search engines, websites, etc. Not just .onion sites. Just avoid logging into your personal accounts.