Spoiler alert: in 10 years a leak reveals that ProtonMail is one of the multiple "Swiss-based privacy-oriented" services operated by secret services.
I believe that there are still honorable companies out there (and I don't even use ProtonMail in particular)
We don't see this at all.
That tells me these services are compromised on some level.
A little while ago I noticed plenty of different VPN providers. Many of the smaller ones were bought and private labelled or had smear campaigns against them. Companies compete so some of that is understood.. but the extent of the attacks tells me players with powerful networks (governmental,business or rogue) shut down many legitimate smaller VPNs whike help promote others.
I would be wary of using any VPN if I expected privacy.
Rolling your own is easy enough but be careful where you setup shop.