You can re-order steps in the UI. Drag and drop but it doesn't always work exactly as you want. However your point stands about the trigger not being able to be replaced easily if at all in some cases through the UI. I only recently learned you could drag and drop in here lol.
My biggest complaint about Pipelines is the fact that it hides so much from you and it also seems to work based on the field name and not the field ID which seems insane to me. If you have a field that has a name change the Pipeline breaks. Not only does it break but a schema refresh won't fix your issue. You need to go to the original, and possibly all, steps the field is used in and click into the box with the field list. This is what updates the step to use the new schema after it gets refreshed, at least as far as the field names go.
I am sure I cannot be alone in hating the error reporting or lack of error reporting. If you have ever used Workato or similar integrations that is beautiful and it makes it super easy to determine your issues. Pipelines seems to do its best to hide what is actually happening under the hood with pointless error messages like "Something went wrong" or whatever. Even looking at the activity log it is incredibly unclear what actually went wrong most of the time.
That isn't even getting into the actual performance issues with Pipelines. I don't see bad performance often anymore but it does happen and it is never clear why. I understand Pipelines is an outside service now but it struggles to do things in a few minutes that an Automation would have done in less than a few seconds sometimes. I am so sad they are taking away Automations and replacing it with Pipelines when it is not a 1:1 service at this point. It is not as reliable as Automations in my opinion, not by far. I wish they just kept Automations like they did with Actions when they replaced that....
We currently only use Pipelines for things that are not business critical for the most part and that says a lot. We have moved everything we can to a service that costs us a lot in comparison but the reliability pays for itself 10x over in many cases. There are just things we are not comfortable using a Pipeline for when it matters if it works. If it can be down for a day or so then Pipleines is a good candidate for moving that data.