Minecraft Java and Bedrock edition's redstone are very similar to each other. The only place where they are clearly not alike are with pistons. The pistons on both versions have pros and cons. Java's pistons can rapid fire and drop blocks, but they are also quirky; especially when it comes to piston update order. Bedrock's pistons can move more kinds of blocks, but they can't drop blocks (since they actually finish extending before retracting), and their update order is random, but in a more predictable way.
If Minecraft will ever have redstone parity, it will not only need to combine the best of both worlds in terms of redstone, but will also need to change pistons in a way that makes them powerful, yet intuitive.
I believe to achieve piston parity, firstly piston order needs to be revamped. It must be easy to understand (like Bedrock) but must also be consistent (like Java, to an extent). By making sure any machine involving pistons works the same way, no matter how many times it