There are a lot of blogging platforms out there. Where should you write?
Before we get into it, the actual answer is to put your best stuff on your own site, a site that you own and have the domain, backups, and an email list for.
Combined my websites that I haven't even written for in weeks get over 100,000 visitors per month. I highly doubt Hive or Medium will ever give me that without serious alliances or publications being involved.
Also, in terms of earnings, I have been on Steem/Hive since 2017 and what I have earned on here is a tiny, tiny percentage of what I have made on my own websites in that time.
But if the comparison is between Hive and Medium, that is less clear, so read on ...
Hive and Medium Stats
Out of curiosity, I looked up my most popular (in terms of views) post on Hive and the version syndicated to Medium.
Only 12 views on each?
Isn't that interesting?
(The views on Hive might well be higher because I only see my Peakd stats)
I always think of Hive as being low traffic and low visibility, but it seems without optimization, Medium isn't any better.
For context, as well as the traffic that Medium might organically send me, I have 6,000 followers there and the content is 99.9% syndicated from Hive. This means a lot of it seems weird to Medium readers because of how much I write about the Hive blockchain :)
I do get likes on there, but one person can give multiple (kind of like Diamonds on DeSo), so it is often skewed.
Remember to be more equal in comparison, I didn't promote anything.
I have a bunch of twitter followers, but recently I haven't been tweeting my own stuff at all since when I mentioned NFTs and got mass-unfollowed.
An advantage that Medium has over Hive is email integration.
I mentioned building a Hive to email syndication service and 
Medium has extra SEO customization stuff and paid plans, but nothing that would make any difference unless you are serious about building out your Medium business. I do know several people who make hundreds of dollars (and more) on Medium by partnering with publications.
The main thing I did not do, and the biggest mistake I made, I didn't include tags in my syndication. I am supposed to go back and add them and I never do! I should include a filtered set in the published article from my script (strip out things like HIVE and Leo-related etc).
So where should you write?
As might already be apparent, I think you should do both Hive and Medium - we should post on Hive and syndicate elsewhere.
Heck if I was smarter I would be syndicated to all the places that allow it.
What a lot of people worry about is "Google duplicate content penalties" but there is no such thing. What people think of as a penalty is a filter - they don't punish you, Google just doesn't want multiple entries of the same content.
Why post on Hive if my own websites have such significantly more lucrative results? On the best months I probably make less on Hive than I do from just one affiliate payment. Heck, my book royalties are likely still 10x for books that are years out of date.
I believe in the Hive platform. Given a change in strategy from the Hive leadership, I think we can beat DeSo and Rally.io, plus some others. It's a long-term play and I am mainly here to learn. Yes, I have neglected my actual business by focusing here lately, but I do think I have learned a lot, especially on the technical side.
Plus, if $HIVE reached DeSo levels, the economics would change real quickly!