I've used the Discord bridge before; it works pretty well, and allows Matrix users to practice better (identity & tracking) privacy if they want. There is none, in Discord.

It does require (a) the Discord community admin to allow the bridge, and (b) some playing with configuration of the bridge to get banning working.

The biggest issue with Matrix is how privacy-respecting it is. Any public forum with anonymous account creation is subject to spam bots, and requires more work by admins. The biggest complaint about the bridge, and why so many Discord admins do not allow it, is because it greatly increases the spam they have to deal with. Kicking and blocking do work fine through the bridge, but it's still a distraction requiring constant vigilance.

Matrix needs better admin tools (where have we heard that before?) Mjolnir is good, but the freely hosted instance was shut down a year or so ago, so it's not available to casual users. And taking on running a service just for a community bridge is a silly requirement.

My points are, that it's not an either-or, but that it requires work. It's a question of commitment, not possibility. c/privacy could have a Matrix-first, privacy-friendly approach and still offer Discord for privacy casuals; it's just harder.