In most situations: yes.
Keeping a European account allows you to maintain part of your savings outside of Vietnam, pay certain French expenses, potentially receive income in euros, and have a backup solution.
A fairly healthy organization could be:
French Bank
→ long-term savings
→ European expenses
→ French deductions
Vietnamese Bank
→ Vietnamese salary
→ rent
→ groceries
→ transportation
→ QR payments
→ daily expenses
You can then make transfers between the two when necessary.