Holding Bitcoin in multiple wallets is the most secure, if you want to keep Bitcoin for a long time in this current situation, then you should use strong wallets. Especially if you use hardware wallets, your Bitcoin will be the most secure and protected, you can be safe in the future, but if you use multiple wallets, your Bitcoin will be much more private.
That is why it is recommended to use multiple wallets, if you have several Bitcoins in one wallet, it may be revealed, so you can face danger with your many at any time. So it is important to keep your wallet in multiple Bitcoins to protect your privacy.
Secure or not, it all depends on your practice.
If you use many wallets but store them all in one device, their backups are stored all in only one place, it is not your good practice, and it's not actually different than other people who use only one wallet and has one wallet backup.
Your practice is only secure if you know and maintain a principle of storing your fund in different wallets, on different devices, and the same for your wallet backups. It's similar with your wallet passwords too because like passwords of accounts, if you only use one passwords for all things, it's very weak in security for your accounts, wallets and anything you need to encrypt it for security protection.