You should not be able to export your private key from any wallet UI

What happens if the app / wallet stops working and you had no ability to back up?

You shouldn’t hold assets you’re not willing to lose in anything besides a hardware wallet

"Should" doesn't work well with average consumer behavior

blockspace babe. cultural attaché from ‘06 twitter. adjacent possible fanatic 🌐 UTC–5

Exactly that's why wallets should be designed with this in mind and why nearly everyone casually exports private keys and stores them in plaintext