To, add on to that. Some of the mods like Tinkers construct became very confusing as they added in more item slots for the part builder or tool forge/station. In 1.7.10, it was very simple. 1.10.2? Things became very difficult to understand and learn.Sadly, this is true. 1.7.10 was a great time for mods, and I'm sure they would have updated more of them to new versions, but some of the best mods are so big that porting them over every time a new update comes out is just to hard. The good thing is that most of the mods in my current modpack are getting updated soon!
Hopefully the last few remaining mods like inventory pets stay the same as it was during 1.10.2 and not add in like some weird pets that require this and this to find.