Where can I find in-depth analysis of different digital card games?
I don't think you are likely to find a one-stop-shop for many different card games (can't say for certain, because proving a negative and all).  Coming up with those analyses are usually things that take some depth and investment in a game to come up with, thus aren't likely to be common / easy to write for a quick blog post to make a few bucks on the internet.
To get the kinds of analyses you are looking for you are probably going to have to dig a bit and use Google extensively.  Think about what kind of resources are more likely to give you in-depth analyses of Magic.  There are dedicated blogs and YouTube channels that regularly analyze metagames, new cards, etc. but they all are catering (primarily it seems) to an audience that is already invested in the game.  It saves them from having to explain the basics so they can focus on the meat of the topic at hand (ie. present the bits that are interesting to that primary audience, not the things they are likely to know and find boring to hear rehashed for the 753rd time).  So those kinds of resources, the kind most likely to be able to present such an analysis, are also the least likely to do so because it isn't going to get eyeballs in front of content (and ads).
The other problem you are likely to run into is that there is going to be a lot of opinion involved.  While the denizens of the internet have no problem or lack of desire to share their opinions on a topic, finding a group that will give you healthy debate to produce what you are looking for is likely to be rare.  What one person considers a strength another might consider a weakness (as your own description of Magic above points out).  But you aren't likely to see a ton of that without seeing both proponents and detractors of a game.  And the way the internet tends to create groups of like-minded people (like sub-redits, Facebook groups, etc.) you aren't going to typically find both sets of people in the same place.  So you are going to have to seek out both and make your own analysis of a game you presumably haven't played yet.
So all in all I don't think you are going to find much of this for any single card game, much less find a place that would have this for a broad range of games.  There just isn't money to be made doing it and the current internet community model doesn't lend itself towards producing this naturally.