Berserker, you probably though about the following, in any case I'd like to hear your thoughts about it:
Some people play the same game since many years, for example Zelda Ocarina of Time, by playing it differently each time. One of the most popular way is to use a Randomizer mod that for example swap the location of many items in the game, with some limits to avoid getting the player stuck. Some players like me play tt2 since many years too so such an idea could be interesting there too, in fact it's already the case for many things: what's inside towns, what are the cells/world resources surrounding the dwelling, how the dungeons/mines look like, but there is one particular thing that is always the same and may (or likely may not, but this isn't even a draft, just an idea I'd like to hear your opinion about) be more interesting to randomize: the technologies in the science tree. My idea is something like, randomizing a bit the cost of the technologies and, for each ages, either making a new tree with randomized techs, or even randomizing what's inside some techs (for example, while "join alliance" and "create alliance" shall stay with the mission, the petroglyph could totally go somewhere else).
If I'm that cautious with such an idea, it's because I know there would be issues, first: since some people could have a very well randomized tree and some be very unlucky, not only it should be totally optional but probably that people choosing that would have to be on a separate continent and I feel that you are against that (well it's the case for collectivism vs despotism). Then, the randomizer shall be coded so it doesn't stuck the player or even force him to take weeks to research something crucial that is at the bottom of the tree and that's not easy.
I'm gonna stop here given how it's likely never going to happen, but I'd like to hear your thoughts. Maybe at least just randomizing the costs of the techs by + or - 20% of their original cost sounds more reasonable/could be a first step ? Another thing could be to slightly reduce or increase the number of technologies required to unlock in one age to be able to research a first technology in the next age.