With that said I've got to say that props can be really nice and there's all kinds of ways to use them. Blocks can help you stay more stable when you can't quite touch the ground in a revolved triangle pose, or allow you to take a restorative fish poses for a great chest opener. We usually think of using straps in poses when you can't reach your toes yet, but you could also use a strap to stretch your neck or shoulders, just watch this video!
There's a dozens other props out on the market, back stretchers, toe openers, inversions swings, headstand helpers and more.
You don't necessarily have to run out and buy a bunch of props to get the benefits. Try a scarf or a belt if you don't have a strap and wrap it around the bottom of your foot for a forward fold, pulling yourself farther forward. Laying on your back, place a few pillows underneath the middle of your back and let your arms rest open for restorative fish.