It depends on what the meaning needs to be.Yeah, I'm not convinced. "Let's remove attrition but then if we want the fights not to be meaningless we can add it back case-by-case basis," does not to me seem like particularly functional or desirable design.
If your goal is for each combat to have "meaning" in terms of challenging the party....well that's not happening now. The attrition model isn't working because people aren't using it (as the OP stated). So most fights are "meaningless" already in that context.
What seems to be happening at most tables is, people have like one maybe two "warmup fight" where the players kick in some skulls and enjoy just kicking butt, and then they have the hard or "boss fight" where there is a true challenge. The encounter model handles that much better than the attrition model does. Or your group could literally handwave all of the "warmups" if you truly want every actual run fight to have meaning. The party cinematics breaks down the door and slaughters the goblins, and the party just describes how that happens. Then you have the actual combat, which is a hard challenging fight with real danger". That also works great in the encounter model.