I'm really glad you brought this up because the wave of absolute, unmitigated, brazen antisemitism I've seen in normie spaces ever since the Epstein files dropped has been staggering.
I'm against the "the elites are oppressing us!" framing for two reasons. One, like you say, is that it's perpetually one small step away from becoming "(((the elites))) are oppressing us!" And you don't have control over if and when that happens. You think Nazis aren't taking advantage of that framing? Slipping into progressive/normie spaces and "just asking questions" about this group of elites? Taking people like Epstein and using them as proof that Jewish people were conspiring against us all along? Dropping Nazi dog-whistles into the conversation to signal to other Nazis that this is a safe space?
If you've already primed people to agree that a small group of elites is shadow-ruling the country, you've primed people for antisemitism.
But even if you could completely remove antisemitism from the equation - you can't, but let's pretend - the constant waves of despair I see from people saying "nothing ever changes, nothing ever gets better, we're all under the boot of the oligarchs and there's nothing we can do about it" is both demoralizing and completely untrue.
People who insist that women, gay people, racial minorities, disabled people, etc., have not made any strides since the US was founded are either lying to you or too stupid to be speaking on this subject. You can acknowledge that injustice and discrimination is still deeply-rooted in our society while also acknowledging that decades and centuries of incremental legislation, organizing, and activism have vastly improved the lives of marginalized people.
If your pitch about why society is bad is basically "things suck, they'll always suck, there's nothing we can do about it", why on earth would I join your movement? YOU don't even sound like you believe in it! If you insist that "the elites" will never let us make real progress, then why would I even try? If you insist that incrementalism doesn't work and only violent revolution can free us, I'm not going to think "huh, I guess we gotta revolt", I'm gonna think "well a revolution isn't gonna happen, so I guess I'll stop paying attention to this".
And frankly, I think it's wildly offensive to the people who spent their lives desperately fighting for the progress that lets me live as myself to insist that they didn't actually accomplish anything because nothing has ever gotten better.
Stop making space for antisemites, stop capitulating in advance, stop ascribing god-like powers to rich people. Stop dooming, start organizing!