Nothing seems to cause more problems than old printers being retired. People tend to get more attached to their printer than any other item of their computers. When they find one that worked well and prints well, they are reluctant to switch.
The first problem is that printers have many moving metal and plastic parts. Over time these parts do break. Soon all will reach a point when they need to be replaced.
Interestingly, if a printer is put on a shelf for a long time unused, these parts will dry and crack. They are not something you can store and leave.
Another problem is that even if the printer hardware is working correctly, often we discover that Microsoft and many printer manufacturers no longer support them. If so, you may not find a software driver for it. This makes them useless, so requiring an excellent printer to be replaced.
Often options people need to consider:
Dump it: Many printers have an internal printer hard drive. As such, a copy of everything you may be stored in the printer. This is why major organisations smash and dump them.
Sell. You can try to sell your old printer.
Trade-in: Some printer manufacturers will offer trade-ins when you buy new printers. Sometimes we do accept trade-in for spare parts.
Relatives: Family members can use it for example kids often need a printer to do assignments.
Recycling. Many companies will take your old machine, for charity. Consider this if you are looking to do something philanthropic. We use this one.