is TiCon still a thing? And did Thaumcraft ever get an update >~<
TiCon v2 is a thing now, all material properties are reworked such that you can now really tinker with different materials giving different features under different circumstances. It is no longer possible to make an obviously best tool for everyone, and you can change tool parts on existing tools without the add-on.
Thaumcraft was the first to update post 1.7, with TC5 being made for 1.8. However, as you noted, 1.8 never became big. TC5 was not updated post 1.8 and is now stuck in its own isolated environment. The TC author is moving on in life and isn't able to work on TC anymore, there is a faint hope, and some indications, that someone else might take over, as has happened with other mods, but I don't know the status on that. (a shame because TC5 might have been the best version of TC ever, but very few people will be experiencing it)
TE v5 has reworked the upgrade and augmentation system and added many new machines with functions borrowed from Ic2.
IE is going strong and adding many new features, but is otherwise still the same.
What is it like these days?
The Energy environment has gotten fractured, with all tech mods removing RF dependencies. Thanks to the new Forge energy API they all work together still, but in my opinion, things appear very messy.
RC is stuck in 1.10 at the moment, BC is stuck in 1.11 at the moment. (and very alpha) Forestry is working fine in all versions, and TE has been completely out of the running for a while but is currently working fine in all versions once more. (by "all versions" I mean 1.10 + 1.11 + 1.12)
Many modpacks include less well known mods, in part just to provide features that would in the past be provided by other mods. (this is not necessarily a bad thing)
All in all, the modded environment is incredibly fractured. Thus, despite the fact that it is old, the 1.7.10 environment is still a good place the be, because all popular mods are together in that versions. Many people are hoping that 1.12 will become the new 1.7.10. (though a.t.m. this is still just idle hope)