Simply because we can’t be all things to all people, and it’s never been part our business. It would be hard to post a four metre tall tree, for starters!
Artificial plants don’t really lend themselves to internet sales, except at the bottom rung of the quality ladder. They never did back in the mail-order days either.
Having said that, if you’re a swipe left/swipe right sort of person, there are plenty of sites selling fake plants out there. Good luck, at least you won’t catch anything!