I had a similar reaction to the new lycanthropes at first. I really liked the idea of silver weapons bypassing their resistance, especially since I'd recently run a game where the party encountered one early in their careers, when they didn't have any magical weapons yet. In those situations, finding a silver weapon was a big deal (and usually a big glowing sign that shifters were in the near future).
But I can see why they removed that trait in 2024. They kind of had to, to be consistent with the way they removed resistance or immunity to non-magical weapons across the board. And in that encounter I referenced above, the warriors didn't have much to do except try to pile onto the thing and keep it from the wizard and cleric, who were the only ones that could hurt it. In one of my other games I had a character who for whatever reason never found a magical weapon (I had put a few out there that they just happened to miss); in mid-level play he was constantly running into things that he was much less effective against than the rest of the party. It sucks to be in that situation, so it becomes incumbent on the DM to make sure that everyone has access to a magical weapon. And if that's the case, what's the point of having the resistance? Just make the monster tougher so that everyone has an appropriate challenge.
I still do like the idea of "here's a threat that our usual armaments can't deal with, so we need to find something special that can do the job." Going on a quest to find the weapon/spell/item you need is a stable of the fantasy genre, so I may create custom monsters to fill that role in the future. I like the idea of the loup garou that someone mentioned earlier, and I found a CR13 version online that looks pretty frightening (it has regeneration that is only stopped by silver).
Finally, the new lycanthropes are still scary; they definitely got a glow-up in terms of AC, hit points, and damage. I'm still uncertain about the new curse effect, as I haven't yet seen it in actual play. But I was putting a village infested with werewolves into my newest 5e 2024 campaign, and when I playtested that encounter they absolutely shredded my party of eighth-level PCs. Now that they can change as a Bonus Action, a group of "commoners" can be on you in an instant, adding to the drama and tension of the scene. In the test encounter the characters retreated into a house that the werewolves proceeded to tear down around them. I'm still going to keep that encounter, just reducing the number of foes to a more manageable number.
