Why should I care why republicans wanted to break up tech monopolies, if breaking monopolies is anyway something that I consider a positive change?

Because they’re not interested in breaking up monopolies; they’re interested in threatening their political enemies with breakup so they can control speech on those platforms. Mark Zuckerberg is kowtowing to Trump now to avoid being broken up.

You think the Republicans are going to break up tech and create a more diverse online publishing ecosystem that’s harder for any one party to control? No, they’ll crush their enemies and bolster their allies, so we’ll end up with even fewer choices