And how does knime/everything else compare with PowerBI, given how aggressively it is being pushed by Microsoft, and the fact that it would come bundled as part of most organizations Office 365 deployment.

When you see it, you understand it. Knime interface is designed around "data pipelines" if you wish, completely different from PowerBI, which seems more oriented to dashboards.

This is amazing. Thanks for pointing out knime. There were so many occasion since and including uni where I wish I could've used that.

It's pretty useful for data manipulation. I use it for very heavy lifting (millions of rows with A LOT of text manipulation, regex, and even some ML) with a Dual Xeon + 32 GB Ram and it's a beast. It takes some time to master, but I encourage you to play with it.

Is it just a better "Excel" or does it have some actual feature to prevent people making mistakes?

Take a look and you'll understand it right away. It's organized with nodes and links. Nodes perform operations, and links transport data between nodes. You can arrange them visually as you please. There's even stuff like "metanodes" that allow you to put nodes inside, so you don't have to have a messy playground.

Most nodes (there are official and 3rd party nodes) do have error output, and there's a console to inspect what's going on.

You can also inspect data visually in most nodes.

Even someone who is not used to play with data, who doesn't understand consistency and yada yada will understand the advantages.

It isn't a spreadsheet.

It uses a visual data flow approach to transform data step by step from one form to another. This approach is much better for data transformation. It is also less error prone as operations take place on columns or rows of data, not cells. But you wouldn't try to create a set of company accounts with it.