NPM was never "too insecure" and remains not "too insecure" today.
This is not an issue with npm, JavaScript, NodeJS, the NodeJS foundation or anything else but the consumer of these libraries pulling in code from 3rd parties and pushing it to production environments without a single review. How this still fly today, and have been since the inception of public "easy to publish" repositories remains a mystery to me even today.
If you're maintaining a platform like Zapier, which gets hacked because none of your software engineers actually review the code that ends up in your production environment (yes, that includes 3rd party dependencies, no matter where they come from), I'm not sure you even have any business writing software.
The internet been a hostile place for so long, that most of us "web masters" are used to it today. Yet it seems developers of all ages fall into the "what's the worst that can happen?" trap when pulling in either one dependency with 10K LoC without any review, or 1000s of dependencies with 10 lines each.
Until you fix your processes and workflows, this will continue to happen, even if you use pnpm. You NEED to be responsible for the code you ship, regardless of who wrote it.