The way I've been looking at it recently is that any defects in the mechanisms of democracy don't just result in more-random results and slightly less satisfied constituents, they're actually exploitable weaknesses that allow powerful people or institutions to exert more power than they would be otherwise entitled to.

We (speaking as a U.S. person) need to do away with the electoral college and first-past-the-post voting not because popular vote and a better election system are nice-to-have features, but because our current system paints a giant target on the political process we all rely on to ensure accountability. When the outcome of presidential elections depends on a few hundred or thousand voters in one or a few of Florida/Ohio/Michigan/Pennsylvania/Wisconsin, that's a systemic vulnerability.

There are active exploits in the wild; this is less a matter of instituting reforms to make things a little bit better and more a matter of adapting to new threats in order to reduce the risk of a systemic collapse.

Other exploitable vulnerabilities in our democratic process that have been weaponized to varying degrees include: Winner-take-all primary states (on the R side), superdelegates (on the D side), gerrymandering, Congressional procedural abuse (like the filibuster in the Senate, or refusing to vote on popular measures if it's opposed by a majority of the majority in the House), congressional gridlock, and sloppy campaign finance regulations.