Not sure what you mean by "secure". If you mean safe from unauthorized access, that can either be via encryption or via access control lists (ACLs). Encryption is popular for external devices in case of loss or theft; BitLocker includes BitLocker To Go (BTG) which can automatically unlock devices when plugged into authorized computers, without having to enter a passcode. BitLocker requires NTFS but other types of encryption might work with exFAT (haven't tried it).

If you have Win10 Pro or better, BTG is easy to set up and use for any external devices with data which are at all sensitive.

ACLs are used by network accounts in a shared files situation but usually are not too relevant for removable storage.

If by "secure" you meant solid and fault-tolerant, yes, NTFS is better than exFAT.

exFAT is compatible with more device types. For a long time if you wanted to transfer files between Windows and MacOS you had to use exFAT. I don't know the current status of NTFS support on MacOS. At one point Linux/BSD-based systems could read but not write (I believe MacOS file system/virtual memory is based on FreeBSD). With a quick Google it seems MacOS can read but not write, that restriction due to licensing rather than technical constraints. It seems there are hacks which can let MacOS write to NTFS volumes.

>No, I didn't want to encrypt the external drive. I just thought that NTFS is more secure than exFAT.
>
>>If you want to encrypt an external device with BitLocker, that requires NTFS.