How difficult is it for simplified Chinese readers to read traditional Chinese?

I'm trying to comprehend what similarity it would have to the eligibility of old English writing to modern English writing which I can read somewhat perfectly - For traditional Chinese, from an outside perspective, it looks much more different

Edit: Really interesting answers, thank you all so much. I was wondering because I had a conversation with a Chinese teacher at a Confucius Institute about it, I wondered what some other people thought about it