Why does Siri on Apple Watch suck so bad?

I had the Apple Watch 4 and got rid of it because Siri couldn't seem to work worth a ****. Constantly acting like she can't hear me or mis-hearing me, etc. Very simple commands like, "Add lentils to shopping list" or "Set a timer for 10 minutes," were too much for poor Siri, yet any of the commands that Siri on the Apple Watch had problems with, I could do on my phone with almost 100% reliability and accuracy. I tried all kinds of things but nothing worked with any consistency. So I got rid of the watch. When the Series 5 came out, I decided to take the plunge and hoped that bugs had been worked out. It worked for awhile, but now I'm back to the same exact problems as before. Utterly ridiculous to fork out this kind of money only to have such consistently inconsistent performance.