Honestly, I don’t think many. Every few months there is some drama usually with the Foundation fanboys shitting on NVK/Coinkite on social media about this exact point. Perhaps someone that is not on social media or hasn’t purchased a coldcard or been to their website over the last year might be under the impression that they are open source. I doubt anybody that actually understands what open source means thinks CC is open source.
Most people probably don’t know the distinction and likely never will or care to know tbh
If every company goes open source then people will just have to pick who to trust based on track record.
And if we are being honest, the vast majority of people still trust even if the product is FOSS. Very few people are actually able to look at the code and know it does what the team or company says it does. The rest of the 99.9% of people trust the “experts” they know did the due diligence and confirmed the software is not malicious. You can argue it’s better to trust many people that have independently reviewed a foss project and arrived at the same conclusion, rather than trusting a company. But for most ppl we are still trusting these people are not lying to us