Yeah I really need to. I do occasionally go through a bout of trying to take my business elsewhere. I am sort of a used book junkie and Amazon still owns that market. Though I do often get my used books from Alibris when I can.
Recommendations for alternatives would be very welcome.
For mainstream books, I use Bookshop ( https://bookshop.org ) or Kobo. Bookshop supports indie bookstores. Both of them will let you know if a given eBook has DRM or not.
(Now, when a book does have DRM, I buy it from Kobo! I'll leave it to the reader to speculate why :) )
Recommendations for alternatives would be very welcome.