What Settings > Account does
The Account card in Settings is identity only, sign-in status and a sign-out button, nothing about usage or your plan.
Overview
The Account card in Settings is deliberately simple. It shows who you're signed in as, and a sign-out button. If you're signed out, it shows a sign-in form instead. That's it.
What it doesn't show
It doesn't show how much translation you have left, and it doesn't let you manage your plan. Those live elsewhere on purpose: a gauge in the nav for how the month is going, and a full Plan screen for everything about your subscription.
Why the split
Keeping usage and plan details out of Settings means they only live in one place each. If the same information showed up in two spots, it could drift out of sync, one screen updating before the other. Settings stays about identity: who you are and whether you're signed in.
For details on the monthly amount itself, see How your monthly translation works. If the app shows an upgrade prompt that doesn't match your plan, see Why does it still say "Get Pro"?