Secure notes and data as they had existed for many years in the Keychain Access app are on the way out. I will defer to MrHoffman's comprehensive User Tip on that particular subject: Migrating Keychain Access secure notes to Notes app notes - Apple Community. Very briefly stated file-based keychains cannot access the Secure Enclave, so Apple is migrating to passkeys and biometrics which can. It's just yet another step in Apple's fanatical approach to security.
1Password definitely offers more features but it's definitely not as secure as Apple's approach. Case in point, 1Password suffered from this very public incident a while ago: https://sec.okta.com/harfiles
I suppose the question you need to ask yourself is which service is more appropriate for your needs, the nature of the security you require, and in which institution will you decide to place your trust... but that's drifting off topic.