That's wild to me. I'm mostly not a fan of browser-based tools, and I was apprehensive of Discord calling things "servers" when they're clearly not (if they lie about that then what else?), but it's been rock-solid for me and for several friend groups for ~6 years. We don't use any particularly fancy features (chat, voice, streaming, various settings changes on all of those, etc), but we use a mix of clients/web/mobile-web, and out of all of us there was exactly one issue in that time (a few weeks were incompatible with a particularly esoteric browser, fixed not long after I reported it).