Their free plan will let you hammer in 5 nails per month into a single piece of wood, but you can't use a different piece of wood each month. For $30/month you get 50 nails, and up to 5 pieces of wood, or for $60/month you can get 120 nails and unlimited pieces of wood, and two-factor (they'll call you before they hammer in the nails, and ask where you actually want the nails hammered). If you want to have unlimited nails, you have to contact them for enterprise pricing.
They will also sell the measurements of your wood and the nail positions to other carpenters.
If you need to build stuff out of wood, you have three options: buy something pre-made, hire someone to build it for you, or hire a team of carpenters to build it in house. Arguably, the third option should be your last choice.
Stretching the metaphor a bit, sometimes it makes sense to hire a team of carpenters, but contract out or buy pre-built a few particular parts that are particularly difficult or complicated.
That's essentially what these SaaS products are supposed to offer. The problem is not that they exist, the problem is that it can be difficult to know when you need or don't need any particular product.