Speaking from a developing nation. Upfront solar costs aren't cheap. Reasons why people invest in solar include unreliable grids which result in power cuts from lack of maintenance or capacity. For new buildings bureaucratic processes are so cumbersome and often there is lots of corruption for you to get connected to the grid so people rather just invest in solar and have nothing to do with often hostile local government officials looking for a bribe to get you connected to the grid. It can take years to get connected to the grid.