Window treatments are so casual now. Sometimes people just drape the fabric, and don't even sew it. You can make tablecloths, pillows, bedspreads- anything out of fabric. Cloth napkins are easy to make, and with placemats make great gifts. I like to make dolls also.
Some people have no choice but to sew, as they are hard to fit.
Alterations can be tricky, and that is another factor in whether you want to sew for yourself. Always buy your patterns at least 50 percent off. You can almost always find them at that price, if not cheaper. A lot of stores will give you the pattern for free if you buy their fabric. If you are going to sew for yourself, you better know which type seams are most flattering on you, as well as other details in the construction.