Some pages disable copying.

I use reader mode on safari. Other browsers have "readability" extensions to clean out extraneous rubbish, and make text legible.

I sometimes have to disable JavaScript for the site (how you do this varies) to make things sane.

I read and save and email lots of articles every day, and it's a struggle.

Some sites have "progressive" images that copy twice. Other images don't copy at all.

Hang in there. If you can disable JavaScript, try to do so.