Actually most of these companies don't offer any 3P API access - or even better only to a few selected partners. Not one you mentioned but Airbnb is a prime ex

Actually most of these companies don't offer any 3P API access - or even better only to a few selected partners. Not one you mentioned but Airbnb is a prime example where folks want to automate things but nothing is accessible to hosts, guests or small scale developers trying to build something. Very frustrating but if you're not happy, use one of the services they partnered with or use something else (oh wait they already got rid of all the competition)