Often the techniques that you need for a harder problem, are discussed in a forum for an easier problem. Even more often the techniques that you need for a given problem are possible to work out from scratch. And the more you work out, the easier they get.

This can be very frustrating for people who are used to being spoon fed techniques, then given problems which use what they have just been taught. But it is a lot of fun for people who enjoy puzzles. If it isn't your cup of tea, that's fine. But don't dismiss it for people who enjoy it.

Disclaimer. I haven't personally engaged in the last few years, but I've spent a lot of time on it. I solved 598 and contributed a couple of puzzles as well. One of which they immediately saw a way to do that I hadn't, and put it out there with a difficulty level that I didn't know how to do! That was https://projecteuler.net/problem=240.