Bitwarden is a means of saving some money and also not putting all your eggs in one basket, so it kind of is an answer to your question.

As others have said, no matter what you use, make sure you have regular backups.

I see it listed further down under the Forums section.

This is disappointing as someone who does not want everything centralized under one company. I have tried to diversify the services I use, but this is the second one that Proton has acquired.

SimpleLogin development has essentially been stalled since they were acquired by Proton as resources were used to develop Pass instead. I have a feeling that Standard Notes will be treated similarly.

So what you’re saying is that you want a Proton web browser next? /s

NextCloud Contacts supports syncing using the CardDAV standard. iOS supports this natively and it can be used on Android with the DAVx5 app. There are also desktop apps that support it as well such as Thunderbird.