I'm sure I've tried Mortadella. I've never heard of it named "Bologna". I don't like the taste or texture, I find it really different from hot dogs or sausages. But, this Mortadella was from Argentina. I'm not sure if the European version is actually like hot dogs and also called Bologna
European here, specifically NL. There is no "bologna" or "baloney" in stores here. We do have "boterhamworst" in stores here, though that is frequently considered a cheap, unimpressive product, compared to more fresh meat. And other countries have their own implementations, often of higher quality thanks to long-standing traditions of sausage production.
Also, though I in particular cannot speak from experience, I have a good reason to believe that if you were to travel to the city of Bologna in Italy, and try some Mortadella there, your opinion will most likely be informed more by better, or at least more representative examples.