> What's missing from these parts which makes people reach for ESP32 by default instead?

I didn’t directly answer that question before.

Strictly speaking, nothing essential is missing from many of these other parts. In fact, in professional contexts they often have better documentation, support, longevity guarantees, or security features than ESP32.

One of the biggest differentiators is simply pricing strategy. Espressif has used aggressively low pricing (what many would reasonably call predatory pricing) to capture mindshare and market share. That playbook is hardly new; it’s been used successfully across industries for decades. Ultra-cheap silicon, combined with inexpensive dev boards, dramatically lowers the barrier to entry and makes ESP32 the default choice, especially for hobbyists and startups.

Price pressure also creates a feedback loop: more users means more tutorials, libraries, examples, and community support, which in turn makes the platform feel easier and safer to choose, even when alternatives might be technically superior.

For teams operating in cost-driven markets, this can become unavoidable. If your product lives or dies on BOM cost, reaching for the cheapest viable part may not be optional. I spent several years in that environment myself, and while it’s a valid constraint, it tends to push decisions toward short-term cost optimization rather than long-term engineering value.

So the answer isn’t that these parts lack features, it’s that ESP32 combines good-enough capabilities with exceptionally aggressive pricing and a massive ecosystem, which together make it the default choice in many contexts.