Individual forges might support a few thousand users if set up professionally; codeberg etc. might give you an order or two of magnitude more. Gitlab has something like 50M users [1] but it's unclear whether that includes self-hosting, I suspect it does.
Github hit 100M users in 2023 [2] and will hit double that before long if trends continue - the figure of 180M is quoted in different places like [3] for the end of 2025.
From the same page: "Developers created more than 230 new repositories every minute, merged 43.2 million pull requests on average each month (+23% YoY), and pushed nearly 1 billion commits in 2025 (+25.1% YoY)—including a record of nearly 100 million in August alone."
At that scale, it's a miracle anything works at all to be honest, and suggests that Microsoft probably _is_ throwing some love, money, and some of the best developers at it just so the thing stays up even some of the time while they're hitting exponential growth.
The current situation sucks, but it's not evidence that Microsoft is being deliberately evil.
[1] https://about.gitlab.com/company/ [2] https://github.blog/news-insights/company-news/100-million-d... [3] https://github.blog/news-insights/octoverse/octoverse-a-new-...
