[looperhacks]

The common problem with Minecraft server implementations is that they are not bug-for-bug compatible, which will lead to certain techniques (especially redstone contraptions) breaking. The technical Minecraft community depends on many implementation details which not all servers support

[Scaevolus]

In addition to the hundreds of blocks and mobs that would need to be implemented properly and rarely are, the lack of mod support is a killer.

The only "complete" reimplementation of Java Minecraft that I'm aware of is Bedrock.

[dmonitor]

Far from it. The versions lack a lot of parity and Bedrock is called "bugrock" by the community for a reason

[Scaevolus]

I edited in scare quotes for "complete" to make that clearer, but I mean in terms of at least having matching blocks/mobs despite many differing details.

[lupusreal]

A lot of the parity issues are due to Bedrock not reimplementing bugs from Java (quasi-connectivity aka "droppers are doors".)

[archargelod]

There are issues other than not ported bugs. Redstone in bedrock is know to be unreliable.

For example, in Java version if you take a circuit and activate it with a button/lever - it would always behave in the same way. In bedrock same setup could have random result. And "random" is something you don't want in a large sophisticated contraption.

I'd guess it's caused by some race-conditions in bedrock implementation, but alas it wasn't fixed in 7 years.

[sandworm101]

There are no bugs in Minecraft, only features that have yet to be fully documented.