Are you truly missing out? Absolutely.

As far as whether or not they'll feel "clunky" and "boring" or if they'll hold up, that's subjective. I mean, don't force yourself to like things that you don't like, but the CRPG subgenre is massive and there's a lot more than just the same handful of popular games that show up in every random Top 10 list. If you can't find something that you enjoy in the hundreds of CRPGs that have been released over the years, then the subgenre isn't for you.

I guess that I have the benefit of experience because I grew up when the subgenre was birthed, so even today they don't feel dated to me because I played them when they were new. I just couldn't imagine writing off an entire subgenre that houses the best RPGs ever created just because I played the newest 1% of what was available, tried something older, and the experience wasn't as smooth as newer games that have been stripped down to be simpler experiences.