Those are about as basic of an action as you can get. Every assistant supports them. But as soon as you want to know something like "how many teaspoons in a cup," can Siri still handle it? What about "where is the aurora borealis visible tonight"?
Another issue Siri used to struggle was trying to play specific music on Spotify. Is that better these days?
And it does fine with no internet access.
Except dictation. Much better with internet access than without.