That's incorrect, if you are able to dual wield you can bonus action attack, the issue is that you get only 1 offhand attack and it doesn't get your str/dex to damage without the feat. Also, after lvl 5 other classes get to multi attack with the mainhand, but the offhand gets only 1 attack. 2 if you get the extra bonus action from thief.

You need to use light weapons though.