Why we can't use simple word document insted of HTML to create websites ?

Question

Why we can't use word document to use as webpage instead writing lots of lines of code to make a simple website.We can add all basic html elements in a word document. Correct me if I am wrong

Answer 1

We can, of course. It will work and all. But if you compare pure HTML code with what MS Word produces as an .html file... you won't recognize your document :)
Ms Word adds a lot of redundant trash code which is HTML-irrelevant. Many automatic services won't accept that code properly and forget about W3 validation ;)

Answer 2

You can save your document as html in Word. But take a look at it with a text editor. It's chaotic and not readable. Would you consider that simple? I think not. Also take a look at the page in different browsers and with different display resolutions.
Word is not meant to create webpages. There once was a Microsoft program called Frontpage which was created to design webpages, but it messed up the code too.
You won't need lots of lines of code for a simple webpage ;) and even if you did: it's worth it, because it'll be better and your very own work instead of that ugly blob Microsoft programs will create for you.