Being a gallery operator has always been fraught with risk. Like any small business venture, there a plenty of start up galleries and only a small number of truely sustainable galleries with a long term future.
At the same time artists have often struggled to achieve the level of representation that thye may have felt they deserved.
Then along came the internet and new channels opened up for artists to promote their work, and for people to view art. While it is doubtful any (current) online viewing fully rivals the experience of actually visiting a gallery and immersing oneself in art, it would be fair to say that over time the online experinence can only become better and more satisfying.
All this has forced galleries to adapt or die . . .
Read more in this article from ArtNet on how galleries and dealers are finding alternatives to the gallery model.