But while I do think appreciating what you have is part of how to avoid the hedonic treadmill, I don't think it's a matter of learning to be happy with a routine.
I've found it possible to make a conscious effort to avoid hedonic adapation, and enjoy novel things without allowing them to become a new baseline. If you can maintain your expectations at the same level, while improving your actual circumstances noticeably above that level, you can maintain a higher level of enjoyment of your life.
Single, full-time working people, especially in tech, start to unlock the ability to travel abroad, maybe even one of those big two-three week Life Changing things to somewhere exotic, but only once in a lifetime or once every few years.
Middle / upper-middle class incomes eventually get to a point of wealth and freedom where they can take vacations abroad multiple times a year.
And I think you need to be even above that level, where you don't have to worry about your base income or mortgages or whatever, where you can have this lifestyle where you can have novel things and experiences all the time. And even then there's a risk people get used to it.