Totally get this. It's part of a bigger thing I see everywhere now. We've traded stuff that lasts for stuff that's cheap and easy to replace. My ten year old toaster works fine but the new blender died in a year. Your grandma's stitch is like that old toaster, you know? Built with care to actually hold, not just look good enough to sell. That kind of work is getting hard to find.
What kind of thread did you use? I did something similar with an old canvas bag, just some heavy-duty upholstery thread from a craft store. That stuff is no joke, and it’s held for years now. I’m totally with @markcoleman on things being made to last back then, not just to be replaced. It feels good to fix something and have it actually stay fixed.