Easiest way: don’t tell them what you do.

Having far more fine control over, of all things, email. Being able to operate an entire domain and control what happens with every email address in it. I now have a different email address for every legal entity I interact with, sometimes on a per-interaction basis. If I get spam, I know exactly where they scraped the email address from and I can set that specific email address (plus or minus any other data such as which domain it’s coming from) to reject with a custom response or display any other behavior in the email protocol, which is surprisingly extensive once you start looking at it.

IT skills are a very generalist toolkit which can be applied nearly across the board in terms of industries, and also to enormously many jobs. Knowing some basic automation and programming, plus the mindsets involved, can get you significantly ahead of the general workforce in a lot of roles, purely because you’ll be able to free up more time that other people spend doing tasks manually.

It’s entirely up to you. I did have a bunch of such certs, but none of them were actually useful for real-world setups; the knowledge I used for self-hosting came from me mucking around on the internet and reading RFCs and instruction manuals.