I quite agree with your sentiments.
There could be other solutions,though:
• Cap the tech military bonus (and military costs increase!) at 50% or 100% (any tech level over 5k or 10k is useless, save for increasing one's NS).
• Cap the shipment of tech based on the tech levels of the nations involved (i.e. you can't send tech to a nation that is, say, 1k+ tech ahead of your one).
• Tech degradation with time (e.g. 0.5% per day for levels above 5k: at that point everyone will have to stay between 5k and 10k).
• ... (other ideas?)
* You could cap the military advantage, but that wouldn't prevent people from using it for NS and range issues, nor for stocking up so that when there is a war and they are knocked down, they are still at the peak of the advantage. Personally, I don't think that's the answer because the only way for new players to have a chance to catch up is to keep wars at the top as destructive as possible. Individual nations, my own included, lost 100k+ NS due to tech damage, and that's a good thing.
* The idea of capping tech shipments such that you can't send to someone x levels ahead of you alone doesn't do it I don't think, unless tech gets cheaper to purchase manually. In that case, that may be a good compromise between abolishing tech trade entirely vs keeping it the same or raising the limit.
* I don't like tech degradation with time because then eventually all nations will just be exactly the same. You would need to implement tech trees to make the game interesting at that point (nation specialization).
The other option may just be doing what a bunch of people are asking for... completely uncapping aid in every sense, and then after the wild west initial craziness, things might settle down? Seems dangerous to me, though.