Hi
As we all know the XZ-Backdoor showed how open source can help to find out how and when things happened. You can look back into the source code, commits and comments to see what happened.
Many started to talk about what it means regarding open source, and also showed that security is a very important part of computers and software.
But the XZ-Incident showed again one of the biggest problems of FOSS (and OSS), the lack of support the maintainers and contributors get. The maintainer of XZ (before he got replaced by Jia Tan via a social engineer attack), talked about mental issues and overall many things to look after. He was the only maintainer for a library that is used in many big Linux distributions but no one thought maybe to help him or support him.
We all use FOSS projects either knowingly or unknowingly (the XKDC comic comes to mind with the Nebraska maintainer project) and we all love and fight for open and free (libre) software. Simply using and pushing it is not enough we need to support the people that code, test and maintain the projects, libraries, programs that we use. If we don't, it will crash down on us sometime in the future.
When a friend does something for you, you say thank you and maybe buy him/her a beer. Why not do that too for a converter you used or some cool little terminal addition you found and now can't live without it?
As an experiment, make a list of all FOSS/OSS things you use in your daily life that you know of, and then look them up to see if they need funding or in general how they stand. Maybe you can donate to a few of them.
Make FOSS not only a philosophy but also a community that looks after each other.
This feature is (in my opinion) very bad when you think a bit longer about it.
You add a dangerous single point of compromise to your accounts. When your Proton account is compromised, the attacker will have access to all other accounts that you have linked, without resetting the password as they can login with the credentials they just gained.
I agree with the others here, do NOT have everything in the same basket. I know it is very convenient to have everything in one place but one thing why Google is such a pain is the monopoly and the vendor lock (you can call it ecosystem but lets be real, it is a vendor that locks you into the products). This also comes back to my first point, single point of compromise.
Yes Proton is build for privacy, even is now switching to be a foundation with solid share holder rules etc. but we do not know where Proton will be in 10 years (it is like with governments, do not give them the tools to control you just because they are nice now, they can change). If Proton would change into a more data collection company/foundation they would have access to many more data points. All webpages/services you linked your proton account with, track pixels etc.
Let's beat Google by being more respectful to users privacy and not by just copying them, let's be better!