Google Trips does make you travel easier … if you make it’s life easier.
It automatically recognizes the email from big name booking websites (e.g. booking.com, airbnb) as well as airline. But if you order is from independent providers like many caravan parks, you are out of luck. You cannot even add them even you want to type everything yourself.
Google Trips also cannot capture the booking or reservation change via phone. You cannot blame them to not having this feature, but practical product should be able to allow user to make change.
Google Trips does have its strength beside the auto trips creation. It provides a easy way to add city (but not necessary add reservation) and downloads offline maps that include Google reviews on “things to do” and “food and drink”.
TripIt offers some kind of automation, but you have to mail to firstname.lastname@example.org, which is an extra step from Google Trips. Airlines and big name booking sites also got good support there: the important fields like date, confirmation number are prefilled. You do have to enter the information for smaller providers, but at least you CAN enter them. Not to mention that you can enter the cost in each item to track the total cost.
My advice? Install both of them. Use TripIt for handling the accommodation, airticket, car hire. And use Google Trips for local food and attraction.