I don't understand why people think this is such a useful thing. Sure it has some good summaries but you can't find all info there whereas man pages should have everything. It's also good that tldr has examples but I think it's something man should more often have too. So why would people rather use this than man?
For example I often forget the order of pattern and file in grep. I can look it up easily in both man and tldr. I also forget what was the short option for recursion. Was it -r, -R or either or something else entirely? I can easily do a search on my pager to find the option in man but there's only long option available in tldr. That's Too Long Don't Want to Type.