RE autoscaling: effective distributed systems design isn't really language-dependent. Java apps can scale just as well as ones written in Go. That said, I can see there being a case for Java apps not making it as easy to build that way. There's definitely a lot of mainframe/monolith-oriented patterns in both the standard library and in enterprise Java culture.
As for the job market and career investment, I'd say this:
Keep investing more deeply in what you're good at. That's your foundation and what sets you apart.
Avoid chasing the "next big thing" based on speculation and trends alone.
The next step in your career hinges more on your ability to think and design at higher levels than it does on lateral moves to another programming language.
Explore languages and technology that you think are interesting, relevant, or can provide value or elevate what you're already doing. The main benefit of doing this is to engage your brain differently and encourage change, improvement, and growth. This will indirectly improve your work and help your career.
I've written a lot of Java in my career and studied it in college, and I've written one app professionally and several hobby projects and utilities in Go. There's a lot to like about it, regardless of its marketability on a resume.
If you're using Gmail, and you're considering alternatives for privacy reasons, then 100% without a doubt, objectively and unequivocably, Proton is the better choice of the two.
There are other email providers with privacy assurances, and yes, you can self-host, but don't let perfection be the enemy of the good.
To address the trustworthiness of Proton directly: I've been a Proton user for about 10 years. It gets the job done. I have complaints, but privacy is not among them.
RE autoscaling: effective distributed systems design isn't really language-dependent. Java apps can scale just as well as ones written in Go. That said, I can see there being a case for Java apps not making it as easy to build that way. There's definitely a lot of mainframe/monolith-oriented patterns in both the standard library and in enterprise Java culture.
As for the job market and career investment, I'd say this:
I've written a lot of Java in my career and studied it in college, and I've written one app professionally and several hobby projects and utilities in Go. There's a lot to like about it, regardless of its marketability on a resume.