I often find holes wear in my jeans between the legs, so I patch them with fabric on the inside and lots of rows of zig-zag sewing.
It’s not a very visible spot so it does not have to be perfect, but it definitely increases the useable life of the jeans considerably.
Lol 😂. I have done it by hand, but it’s tedious and time consuming. Yeah, a sewing machine is the way to go.