Not being subject to the UK and US surveillance laws seems as good an argument as any.
Though I'm not sure if the GDPR allows for data to be stationed in Switzerland. It's not EU but it is party to a lot of treaties so it's not out of the question.
Ironically it might become a safer place to station data if the EU manages to push through more surveillance decrees.
Don't trust a company just because it's situated somewhere. When governments friendly to yours want to spy on you, they don't necessarily let borders stop them.
> The US and Germany used a Swiss company to sabotage encryption for years
CryptoAG and the CIA's decision to release the history document of that operation is such an interesting story. In particular, it had this effect of getting people to distrust Swiss companies, for better or for worse. It makes it sound plausible, if however unlikely, that a company such as Proton is actually a front for US cyber warfare. (I don't think it is but it might be; it seems like that may have been the point.)
If the EU was starting to go rogue like US is, it could easily bully Switzerland to force their hand into giving whatever data they want to, given that Switzerland have no frontier with sea or non EU country (not that I can imagine this scenario happening, but Switzerland is a weird choice to hide from EU)
Though I'm not sure if the GDPR allows for data to be stationed in Switzerland. It's not EU but it is party to a lot of treaties so it's not out of the question.
Ironically it might become a safer place to station data if the EU manages to push through more surveillance decrees.