if I never back up my iPhone then gets disabled "connect with iTunes" apears will everything ease

Yes. Also see: If you forgot your iPhone passcode - Apple Support

Be design, if a device is disabled it must be erased by restoring it in order to reset the screen lock passcode. There is no way to avoid that process to recover a disabled device. So without a backup to use to subsequently restore your data, yes, you would lose everything.

And ignoring the specific issue of a disabled device, what about if your device is lost, stolen, or breaks? How are you going to restore your data to a replacement device without a backup?