AのほうがBより美味しい

BよりAのほうが美味しい

AはBより美味しい

In all cases, "A" is tastier?

のほうが　/　は　　is always something better, but より is always something worse?

Question

AのほうがBより 美味しい

BよりAのほうが 美味しい

AはBより 美味しい

In all cases, "A" is tastier?

のほうが　/　は 　　is always something better, but より is always something worse?

Answer

You can also say "AはBよりまずい".

"は" and "が" - they are subjects that connect directly to adjectives.
・Aのほうが おいしい 
・Aは おいしい

”より" is just used to say "than".
So, it doesn't matter if it's better or not.

I'm sorry for my poor English.