For example, a CRA self assessment including CE will require around $20k in liquid capital that you need out of pocket even if all you want to do is sell a single piece of jewelry with some electronics embedded into it. Not to mention the indirect costs such as guaranteeing 5 years of security updates.
There is also the issue that PLD for cloud services effectively means that you cannot easily update your software anymore while it is under investigation by a claimant because that could constitute destruction of evidence. This leads to a catch 22 with the CRA, where you are legally obligated to patch a security vulnerability within 72 hours.
The conflict here is that for physical products, the owner receives a unique reproduction of the design plans, whereas with cloud software, the customer is using shared infrastructure that can affect other customers if it is under investigation. So the entire cluster running the software turns into the equivalent of a smartphone. If you want to sell an updated product, you need to sell a new smartphone aka run a new cluster.