I’ve used Thorium (not as my main browser) and I like it. Decent privacy features, performance does feel better.

Some major downsides though:

1. It is not frequently updated to the latest Chromium patch; there have been times where Thorium has lagged three major versions behind. And just forget about getting patches that fix major security vulnerabilities until the next major update.
2. The browser is heavily opinionated, and while that has resulted in a browser with a half-useable version of the Chrome refresh, see this issue and it’s clear the focus is not on privacy.

If you want a browser that’s more focused on privacy and don’t care about the eye-candy that Thorium provides, the Cromite browser is only doing security + privacy patches, has toggles for more permissions, has V8 disabled by default, allows for automatic clearing of history, allows you to change the default referrer policy, has more chrome://flags, and actually gets updates frequently to the latest patch.

The desktop client logs and sends lists of currently running processes by default, and they also collect usage data (which channels you open, how long for, who you’re interacting with). In the settings, there’s literally an option for “Use data to customize my Discord experience”. And sure, they don’t show ads, but their third-party integrations do. Article with sources

In the end, processing and storing millions of texts, images, videos and files permanently, and hosting all those live voice and video calls, and making updates to the clients, will always cost more than what they get from Nitro and server boosting. Discord isn’t profitable; they have to make the deficit up to shareholders somehow.

At least you can block some of the telemetry with uBlock or similar

By default, sure. But uBlock is way more powerful when you configure it. Seriously, take a look at their wiki. I doubt that Brave lets you choose exactly which domains to connect to on a per-site basis. And do you really want an advertising company to make your adblocker? They’ve done shadier stuff.