In the US system you can have split control - one party has the house and the other the senate (or the presidency - you need a trifecta). If you don’t have all three then basically nothing gets done.

This can’t happen in a parliamentary system. There’s only one body, and elections are automatically called if no one can establish a majority coalition. Someone has to have a majority in parliament, and there isn’t any other body to contend with.

Parliamentary systems can almost always conduct business is hyperpolarized conditions; the US system almost never can.