Paper wallets can suffice, but it entirely depends on your threat model. If you're concerned about them getting damaged or destroyed via fire, water or anything that could potentially come in contact with them, a metal wallet tends to have higher security based on that. However, the major concern would probably be physical security such as theft. If it's safe from theft, then the other outcomes are relatively low.
The other outcomes leading to losses are much lower considering that OP has dual backups in different locations. The possibility of both backups simultaneously getting damaged is infinitesimal.
With the risk of theft. Paper is far more inconspicuous than a metal backup.
The only thing that really makes me feel unsafe with paper backups, is the fact that the ink could fade after 20-30 years.
You would check up on your backed up seed phrases more frequently than a couple of decades and would identify any wear in the ink or paper before it becomes unreadable.