Sure, sure buddy, I'll encrypt all of my PII data so nobody can access it... including the web application server.

Okay, fine, I'll decrypt it on the fly with a key in some API server... now the web server had unencrypted access to it, which sounds bad, but that's literally the only way that it can process and serve the data to users in a meaningful way! Now if someone hacks the web app server -- the common scenario -- then the attacker has unencrypted access!

I can encrypt the database, but at what layer? Storage? Cloud storage is already encrypted! Backups? Yeah, sure, but then what happens in a disaster? Who's got the keys? Are they contactable at 3am?

Etc, etc...

It's not only not as simple as ticking an "encrypted: yes" checkbox, it's maximally difficult, with a very direct tradeoff between accessibility and protection. The sole purpose of encrypting data is to prevent access!