Have yourself a car boot sale and you’ll be amazed at what people will buy. They like carrier bags and hold-alls, even if there’s a wonky strap. And even if you don’t get a buyer, you’ll find someone who’ll give it a home. If you haven’t got that much stuff to sell, get a few pals together and do it jointly. It’s actually great fun.
Also - Louisa will like this - it’s a good way to re-use the plastic bags that you can’t help accumulating, as the boot sale shoppers still expect to take their purchases home in a bag.

One of the best uses for tired old backpacks and rucksacks that I know of is simply to scrap them for parts! you can take old strips of the cordura nylon commonly used on packs and use them to reinforce the seams on your new pack or you can even sew them into new pockets and compartments on your new pack. Look at several pack designs online for inspiration and then create your own Franken-pack!

Old day packs work well as tool bags, (circ saw, router, etc). They keep the shop dust off, are easy to grab and go mobile, and much simpler than the hard cases most tools come with.

Take it to a shoe repair shop to restitch the straps and install a cew zipper.
Sandra

The thing with straps is that just doing one seam makes it likely to just shred and fall off.

Reinforce the material of the last 2 or three inches of the strap - use a sewing machine to stitch both across the width, and from the tip to about 3 inches in.

You might also consider reinforcing the material on the bag as well.

I’d take off the other strap and see if you can convert it into a courier bag - there’s only one strap and it goes all the way around (including the bottom). A bit like a purse.

Make it into something you can hang on the back of your door - as a misc. item holder.

Another use is just to use it to hold stuff in your house. The strap doesn’t really need to work if you’re using it to hold, say, out-of-season clothes, or toys, or extra plastic bags, or…