There's lots of factors affecting how accessible a "classic" is, change of language, pace, understanding context of the era, how well characters and themes can be recognised and good old enjoyment. Also how you've been exposed to them, was it for your own pleasure, a tedious study, from an engaging adaptation, exploring an author/ genre.
Some I've got into, some I haven't.
That Pride and Predjudice came out just as I started GCSE English and we studied Jane Eyre as our first text and our class had a good appetite for it. It was a good moment for exploring Jane Austin and the Brontes.
I studied Hardy's The Return of the Native at A-Level. The first section of the book was entirely about describing the moorland before the first human character was encountered. The pace was incredibly slow, and it was a couple of hundred pages in before anything of mild interest occured. It was alright in the end and a fairly intetesting subject for essays, but I've never picked Hardy up for pleasure.
Dickens, I've read some for pleasure. They can take a while to really settle into and fully grasp the role of characters.
I really enjoyed dystopias. Our core text was The Brave New World, and then we were given samples of other comparable texts and had to select one to read independently for comparative work and I chose to read many for the pure interest. The (often early) 20th century language is more accessible, but the themes (like much of Shakespeare) transcend time well. The context of 1984 being written post-war is also well-understood.
A poster above referenced Mr Rochester's wife in the attic; while no angelic character, in historical context he treated her relatively kindly with some dignity. Better to be protected with 1:1 care at Thornfield than locked away in an assylum. Other contexts such as the finer points of post-Napoleonic society are not my strong point.
Classic literature generally endures for good reason. I tend to not get on with many contemporary prize-winning novels and often find them try-hard. Some will become classics, many will not. I'd deem Harry Potter to be a recent contender as a classic because it's proving to be loved by new generations, and is likely to continue to do so because the characters and themes transcend time. There is little to date heavily in them.
There's value in reading classic texts because they have a role in understanding the world, past and present, and they are always a feature on the school curriculum in some form for good reason. Reading for enjoyment is important (whatever the text) and it's a mentally healthy passtime. Slogging through "classics" just to show how cultured you are has little merit.
Admittedly there have been some where I've ploughed on because I wanted to know that text/ story. The Lord of the Rings was one, travelling pre-kindle and having no other distractions helped
I'm not morally superior for having completed that epic journey though (and I've never met made it through The Hobbit!)