Travel websites often charge extra for using some credit cards, most airline sites do not. We don’t know this till much later in the process.
If you want to change things, its better if you booked directly with the airline. Also, if you want to speak to anyone, some travel sites charge you (!) but airlines do not.
If you are looking for a combination of ticket/ hotel/ car rental, travel sites WERE better but most airline sites now also offer this.
Book hotels through rocketmiles.com or kaligo.com that give you extra miles for your hotel stay, with many airlines being partners. Else directly through hotel loyalty programs that you maybe members of, like SPG, Hilton etc. Last but not least, book hotels from lovely boutique stays, my favourites are MrandMrsSmith & Small Luxury Hotels.
Ticket conditions – can you cancel, change? are very important. Most travel sites don’t tell us enough about this, but airline sites do better.
Some travel sites entice us by saying they will compare with multiple other sites, but that often involves opening up an internet window for each site…its too cumbersome for me!
Travel sites often auto default that you buy certain features like travel insurance….it happened to me and I didn’t realise it at first. Avoidable.
Use travel sites to guide you to certain airlines, then go to the airline sites to book.
The proof of the pudding is in the eating
In the last 12 months I have been on 11 trips, having used airline sites for 10 and a travel site for the 11th. I have tried zuji, skyscanner, farecompare amongst others, but almost always found the airline site better.
The one time I used a travel site, I found that it had auto defaulted my buying travel insurance that I had not noticed before clicking “buy”. After doing so, I got an email on my tickets and a 2nd thanking me for buying travel insurance! When I tried to cancel everything, I found it would cost me a lot. When I tried speaking to someone, was told it would cost U$13 just to do so! I finally went to a (free) chat option and then they cancelled the travel insurance.