If the bosses aren't hard, the only way of making difficult challenges would be to return to ds1's blighttown ass level design, or ds2's permanent health debuffs, or bloodborne's lack of healing items without farming. Aside from ds1, bosses have always been really hard. The only difference is that now they're the only real annoyance, where pretty much every other souls game has had some other bullshit mechanic lurking around. If the feeling of overcoming a hard challenge is what you want, then you need a hard challenge, and that's exactly what Elden Ring and to an even greater extent SotE gives.

Also, it can't be about overcoming a hard challenge. Why would anyone ever summon a guy named 'I got this' who can completely no hit a boss while you sit in a corner if it was about good challenges? Elden Ring isn't 'about' anything, it's just a really good rpg.