Why don't all browsers parse text links?

I was thinking today about how all the time people need to copy/paste text links they find on the internet.

I know there are many extensions that add the functionality of parsing text links, but shouldn't this be a feature automatically implemented in most current browsers?

I can't think of any good reason not to have this option available, since I'm sure millions of people each day need to tediously copy/paste the addresses of sites they find in these all-text areas of the internet.

If anyone has any thoughts about this I would love to hear your input.

Browsers interpret HTML, and HTML code has explicit tags to mark a string of text as a clickable link.

If it weren't for that, then web designers wouldn't have the freedom not to make an URL clickable, not to mention that browsers would misinterpret certain character sequences as a link when it isn't (i.e. anything starting with "http" or anything in a word.dot.word format). Of course, sometimes it might just be laziness on their part.

Seems to me that since you say there are extensions to add this functionality, everyone should be happy with the way things are.