What did happen was that we lost obscure words that could only be understood by looking at Chinese characters (because they're used so rarely, or because they sound the same as another more common word) - you could still use them if you wanted to, but unless you also write them in Hanja, it would be confusing, and if you mix gratuitous Hanja into your writing just because you like those words, most young readers will find it pretentious, and I fear, mostly unreadable.
I can't say we lost much by losing these words. Rather, I think it actually forced writers to select less ambiguous words, which is usually a good thing.
(Also, these days most Koreans know much more English than Classical Chinese, so English loanwords can sometimes fill the gap. It helps that most English (or other Western) loanwords sound different from native or Sino-Korean words, so there's less chance of collision.)