I think it's straightforward to make an argument that many of today's conferences are as bad as journals, accepting submissions is only one way conferences filter. IRL they are prohibitively expensive to enter, let alone attend (but again, see "Zoom"), and therefor eliminate all but the elite, they are run by commercial entities in all cases with more than ~200 people, they are more or less required venues for networking and therefor selling yourself for a tiny chance at academic permanence, they give plenaries to elites (filtering to one voice), they have special symposia by invite only, with other submissions dumped to inaccessible parallel sessions (which one will you choose to see?), the submissions you make are published in much more ephemeral ways, and tend to be more difficult to discover in the long term, making the event important but the research not as much (at least in my experience), etc.
Nor do journals.
I think it's straightforward to make an argument that many of today's conferences are as bad as journals, accepting submissions is only one way conferences filter. IRL they are prohibitively expensive to enter, let alone attend (but again, see "Zoom"), and therefor eliminate all but the elite, they are run by commercial entities in all cases with more than ~200 people, they are more or less required venues for networking and therefor selling yourself for a tiny chance at academic permanence, they give plenaries to elites (filtering to one voice), they have special symposia by invite only, with other submissions dumped to inaccessible parallel sessions (which one will you choose to see?), the submissions you make are published in much more ephemeral ways, and tend to be more difficult to discover in the long term, making the event important but the research not as much (at least in my experience), etc.