1. Reddit communities tend to get too large
2. Subreddits overflow into each other too much through cross posting and brigading
3. Post history being public meant that you could get banned/brigaded for your comments on a totally different subreddit (i.e. bots autobanning you on one subreddit for posting on another subreddit).
The magic of discord is that everyone in the server I frequent I either know personally or they are known by someone I know personally. It creates a nice fabric of community and trust. Literally zero moderation over the past 10 years as everyone knows each other and behaves like normal adults and we also don’t get all up in arms when someone says something controversial.