TFA, with its flaws, had rebooted Star Wars successfully and people were hooked. TLJ had an ideal holiday placement and frankly very little competition (Jumanji surprised but that still not much competition). After first viewing, it had horrible legs and took a giant shave from where TFA was financially. Merchandising is down big. Most Star Wars merc. is back to original trilogy stuff. Solo got hammered despite being an ok movie and the studio is re-evaluateing what the heck they are going to do going forward.
Going by simple financials is a pretty shallow push back. Additionally, when adjusted for inflation it is no where near the highest grossing Star Wars films.