For me, I only use these 3rd party booking if the hotel I need to book is not belong to any major chain and dont have their own booking system.
But I always try to avoid these first, and only when I really desperate then I use these 3rd party.

In my experience, booking hotels from major chains using these might get you cheaper price but have issue when you need to modify or even cancel the stays.
The hotel waiting for the 3rd party to contact them for any modification and the 3rd party take their own sweet time to contact.
(and good luck if you need refund both will blame each other)