What, exactly, constitutes a good platform?

[StanLarimer]

I could use some quality input on the following topic for another article that I'm planning:

What, exactly, constitutes a good platform?

In a clear cryptomegatrend, a number of leading chains are beginning to be marketed more as a platform than a currency or asset.

1.  What are the minimum essential characteristics to qualify as a "platform"?
2.  Which of the top chains are explicitly making that claim?
3.  Which other chains would also qualify as a platform if they thought about it, and why?
4.  Which of the top chains do not qualify as a platform, and why?
5.  What characteristics/metrics should be used in selecting a platform for a new project?
6.  What links have you seen to any existing articles on this topic?

Don't feel you need to answer all of these questions.  I'll take any profound insights I can get.

[tokeweed]

I think fuseleer of emunie made a claim that their network can scale to 2000+txs/s and that it is truly decentralized.  No delegates or supernodes or whatever.

So I guess in crypto, stick to the basics and let's start with decentralization in the truest sense (like how BTC started with CPU mining) and scaling that to Visa like proportions.

edit:  Here's the emunie topic:  https://bitcointalk.org/index.php?topic=1191535.0