Yeah, a lot of us learn that the hard way. Partly because a lot of semi-scrupulous sellers market them as leather machines. You could put a bigger motor under the table and a torque increasing speed reducer. But you're still limited by the needle and thread size.
But ... Let's talk about these Pfaff's! I haven't found one yet because they usually bring a premium price. You have multiples!
I believe Singer bought the rights to make a machine based on the 130. If you look at Singer 306's you can see the similarity. A friend of mine recently found a Singer 206, of which I am most envious. It's a pint sized version of the 306.
You have a great machine and I suggest you look into making some denim bags. I made a bunch from thrift store jeans and people loved them. The skills you learn will mostly translate to to a bigger machine, once you find one. Then just start keeping an eye out. I started my industrial adventure with a Singer 111W153, commonly called an "industrial walking foot" machine which is a good range to land in. It's a good all around general purpose machine. Many other kinds serve equally well, maybe better in some cases.
Have you looked at Wiz's treatise on leather sewing machines?
https://leatherworker.net/forum/topic/25239-the-type-of-sewing-machine-you-need-to-sew-leather/