Bitcoin

Bitcoin is still the deepest project in the space.It is worth following the developments and strands. Bitcoin (and Bitcoin Core developers),Bitcoin Cash, Bitcoin Private, Bitcoin Gold ... principles, ideologies, technology, the strengths of the teams, governance and the leaders come together.

The Many Faces of Bitcoin uncovers depths of the exploration of the new brave world. In particular, Bitcoin as a development of Shannon information theory and Fundamental Misconceptions are worth to appreciate.

A trip to the moon requires a rocket with multiple stages or otherwise the rocket equation will eat your lunch... packing everyone in clown-car style into a trebuchet and hoping for success is right out.

So-- Does that mean that Bitcoin can't be a big winner as a payments technology? No. But to reach the kind of capacity required to serve the payments needs of the world we must work more intelligently.

More advance discussions

Nobody Understands Bitcoin (And That's OK) by Jameson Lopp
A good walk-through the technical history and a discussion from the developer's point of view

Bitcoin Post-Maximalism by Paul Sztorc

BITCOIN-IS-WORSE-IS-BETTER this article discusses the history and the opinions about "bitcoin discovery"