iCloud reminders vs. CalDAV reminders?

Which features do iCloud reminders have over 3rd party reminders (CalDAV)?

The support page here says

"All Reminders features described in this guide are available when you

use updated reminders in iCloud. Some features aren’t available when

using other accounts."

Add or remove accounts in Reminders on iPhone - Apple Support

What features exactly will I gain/lose by switching between iCloud reminders and 3rd party CalDAV reminders?