I don't know about the last sentence. It absolutely should NOT be the case that you have to actively block thousands of bots and skimmers to succeed on Medium. I'm not doing it. I do hope that is not the case!

As for trimming articles. There's nothing like word count limits on big topics to make you good at cutting. When I started out writing for magazines, it was a baptism of fire trying to fit big subjects into 800 words, without losing value. It gets easier with practice, and as you say, you're probably improving all the time.