There's nothing streamlined about any of these.
Booking a flight is obfuscated and you'll have to comparison shop across multiple websites or even devices to get the better deals.
Same with hotels - they have tons of rate obfuscation and you have to cross shop their individual websites and the aggregators as well as third party discounts to figure out best deals.
Concerts are similar but different. Sometimes they should be selling tickets via lottery but make everyone fight over them. Other times there are presales. Other times you have to shop through scalpers. Arguably tickets are less painful than the other two, but they're still a manipulative mess where you waste a lot of time.
When I was the A/B test engineer at Travelocity I proposed a test to automatically select all default criteria from a search so that a user was instantly dropped into check out after entering search criteria in the homepage. It was never approved:(
> Booking a flight is obfuscated and you'll have to comparison shop
Wrong. Searching for which flight is the best to book is obfuscated and needs comparison. Which is not what they are banning.
The actual booking, the purchase of the ticket, is as streamlined as you can get these days.
United is the airline at the local hub. I fly with them. It's easy. I have their rewards card. Using 3rd parties that obfuscate is a you problem.
Disclosure: I have never cross-shopped for any of these services. I use Google Flights, Google Maps for hotel search, and book on the hotel website.
What percentage of the total value is typically saved by those who check different devices, browsers, etc?