Forcing every kind of interaction into a singular "feed" is one of the biggest design issues of social media.
I can't call it a mistake, because it's very much not. It's meant to create the perception of convenience and simplicity, as a way to distract from the insidious fact that it demands all participants on the platform to compete for an arbitrarily finite slice of follower-attention. It goes really well with visibility-control algorithms.
By nature, this design will create cultures of conformity and compliance, at the expense of those who are different. This is a huge part of how tech design reinforces the Fedi's cultural whiteness problem.
Community cannot and will not thrive in an atmosphere of forced similarity. Whatever tools of digital community emerge, they will, by necessity, work very differently than social media.