I agree that advertising companies take too much off the top and a lack of competition has probably made that worse. That's also an issue with a lot of publishers, many of them make buckets of money but still pay writers/editors/other staff poorly. That's just normal capitalism stuff that won't be fixed until there's a major global economic shift.

In fact prior to the Internet there was no third party advertising middle man between say newspapers and the actual advertisers paying for ads.

Right, because there were very few newspapers, and all of them were well-known enough that finding advertisers was not difficult. Independent creators and smaller publishers don't have the brand recognition or massive initial audience to make that happen. You can see this in action with a lot of YouTube channels; most of them only have access to YouTube's own ad system and offers for in-video ads from shady companies and mobile games (Better Help, Raid Shadow Legends, Opera, etc).