Again, you own your code dependencies[0]. A patch would be quickly released by software security experts, which every half-competent developer could apply to their product on their own. That's the benefit of ownership - you get to fix things. With software, you don't even need spare parts.

Depending on services is where the fragility starts. They're single points of failure, unless you have a plan to quickly switch to an equivalent competitor.

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[0] - Unless they have a time-limited commercial license. Then they're essentially a service.