In an ideal world, you want to spend as little time on pool maintenance as possible. While you want to keep your pool safe, hygienic and working well, you don't want this to be too much work.
Maintenance costs money, both in labour and resources. If you have to close down the pool to work on it, then your guests can't use it when they want, which won't make them happy.
Sand filter systems work nicely on their own — you don't have to do much work to keep things running smoothly. Some other systems, such as those that use cartridge filters, need regular cleaning. You'll also have to replace the cartridges periodically.
Sand lasts for longer in filtration systems. It does lose some of its rough edges eventually, at which point you need to replace it; however, this typically takes years.
You do need to clean the sand out periodically to remove its filtered debris, but this is usually a quick and easy process. You press a button to set the unit into backwash mode. It then runs in reverse and releases all its filtered material so you can get rid of it. This shouldn't take more than a few minutes.