I learned ABAP in a literally one weekend and was able to make stuff really quickly. For the most part, you could just "loop at <giant_table_name>" extract what you want and show it on a screen using one of their existing ui components. There was not much UI to worry about and you know the user is getting a proper input box (for example) with a working typeahead. Honestly, I thought it was a very decent developer experience. I could focus on what I needed to do and not worry about how pretty the thing looks or if I'm querying the database optimally. I ended up writing a very complex genetic algorithm implementation to calculate optimal schedules and it was a joy.
Yes, the table names were basically in german, and abbreviated, and most things were only 8 chars long for some legacy reasons, but it really wasn't that hard to learn that VBAK was sales_orders and VBAP was sales_order_items and move on.
For the most part, the users were totally fine with SAP. It was hyper-focused for the tasks they needed. It was consistent and easily documentable. It didn't crash, it loaded super fast, it didn't eat up gigs of memory. You just load up the gui application and you don't even need a mouse once you know the shortcuts.
Having spent the last 10 years building web and mobile apps, working with salesforce and others, I miss ABAP very often.