Ask HN: Why YC accepted so many teams doing duplicated topics

YC's portofolio companies, Vellum, Stack AI, AgentHub, Flowise, to name a few, are doing very similar topic, i.e., no-code/low-code LLM-app builder.

Does YC encourage internal peer competition? Isn't this a bit unfair for the founders selling 7% share for this unnecessary and awkward situation?

In addition, given Sam's complex roles across YC, OpenAI and many other companies, it seems OpenAI is conducting everything it can to kill any AI startup sprout regardless of costs.