So the subject of the thread, IP/IT/IS vs technique:
You can have internal strength/power without any aikido technique.
To train internal strength/power, it's very helpful to have specific techniques (not necessarily aikido techniques, mind you) to condition and build skill in the mind/body unification required for internal strength/power.
To APPLY internal strength/power to another person, it's helpful to have a framework to train this. The 12 basic techniques in aikido, in my opinion, provide an excellent framework to train to apply internal strength against another person (presuming you have the baseline skills and can work on them independently - which you'll need to do), especially from the perspective of jin, body connectivity. I'm also highly suspicious that there's a gokui built into the practice (especially due to the anecdotes and commentary from some of the giants about the importance of atemi) where at any point in time you should be able to release a huge power dump into the other person (somewhat equating to the Chinese fajin term) which would give a very nice justification to the reason for the importance of jin/connection and the distancing/body points of contact that the practice seems to place importance on. And interestingly, the formal version of the practice is still an excellent framework to set up the ideal situations for all of those internal strength checkpoints and applications of aiki and fajin.
Still one of the reasons I love still having the framework of aikido as my main expression of internal strength (both philosophically and in physical practice - entering, connecting and controlling the situation to protect yourself and others from harm as much as possible, while having the strength and practical skill to end an encounter as suddenly as needed through the ability to release a shit ton of power
). Plus, it's fun.