I run a small business using the regular 2018 iPad. I have a portable Bluetooth keyboard and the Pencil. I mainly use the pencil for note taking, signing documents and image editing. I have to post a lot of images on social media and I find the pencil really useful. The keyboard is mostly used for blogging.
I have an app for invoices and another for accounting. Everything syncs to my iPhone - ie I can do imaging/invoices/accounting on the go if necessary and everything will then sync with my iPad.
As for watching videos and casual web surfing. Unless I’m on holiday I rarely have time for that!
It’s basically my laptop replacement. Would an iPad Pro do a better job? Maybe. Would I ever get that extra money I spent on a Pro back in extra sales? Probably not. Would I buy one of the new iPad Pros? - maybe, they look kind of cool