56 Personally, I try to specialize in a few mods and allow NEI/JEI to tell me the rest. If I want to learn a specific mod I just create a custom profile on Twitch and have that mod plus Waila and NEI/JEI.
58 back then there was a lot less to specialize in. Modpacks where a lot smaller and the biggest mod was probably something like thaumcraft which also was a lot smaller though, not less interesting.
Back then you also didn't have those fancy gui's to select input/output. Though, at the end of its life that did become a thing thanks to TE if I remember correctly. Another major difference was that though there where different power systems it made more sense that they where different.
The major power systems that existed where MJ, EU and perhaps redpower's bluetricity or whatever it was called. EU pretty much only had machines that took items and produced something else. It did have a miner and pump but neither was exactly ideal.
Meanwhile, the MJ side pretty much only had things that interacted with the world, think of quarries, builders and farms.
This caused the divide to make sense, at least in my eyes. Electricity (EU) is very good in factory setups but is not ideal when you had a lot of moving parts that also had to heavy work like a quarry. This was reinforced by the fact that EU had energy loss if you transfered it.
Meanwhile, Mechanical power (MJ) was the opposite, very good at big heavy work but not so at the fine work that EU could do like cooking a chicken.
Also the ways to create the energy played a major role in showing this divide. To create MJ you needed engines like the steam or combustion engine. Maybe its in my mind but the word engine feels like it is dealing with a lot more raw strength then something like a generator.
Nowadays though, its all RF and even when you have a pack that contains multiple power systems its hard to nicely show this divide and even if you manage to do so people will dislike it. Which is a shame as even in real life, there isn't one type of energy that rules all. If there was we had electric anything a lot earlier and as there where ways to transform power from one type to another though at a heavy cost also that was nicely simulated.
