And you think this is funny? A dilution of the Mod? Really?
T-brd really needs to weigh in on this.
OK.
I did start off with all levels being possible right out the gate, but found that it made the swing between the difficulty levels too severe. The easier difficulty levels would easily get super high bonuses and the hardest would helplessly careen into being economically choked off from nearly any research being possible at all, exacerbating its own problems.
A happy medium was found by gradually unlocking the severities of the education levels, and it logically made sense as well because as there is more for the average person in a society to learn, there is a wider and wider potential gap between the society that is largely up to speed with modern knowledge and one where the people are desperately undereducated.
The progression of unlocking further depths of possible undereducation and high education penalties and benefits with each lifestyle era has become not only an almost perfect curve for balanced gameplay, it also gives a lot more strength to the interesting decision of when and how aggressively to shoot for unlocking the next era as well. If you've been letting your education slip, whether due to negligence, distraction, or strategically to help grow your cities faster or diminish your anarchy by letting it falter in the capital in preparation for a large set of civic changes or to help diminish war weariness, then charging into the next Era should be delayed, even if you aren't using Beeline stings, because you'll get hurt further by the new degree of undereducation penalties that open up there. On the flip side, if you are truly prepared to enter the next era because your people are heavily enlightened, great, do it asap to get as much modifier benefits as you can as quickly as you can. It makes a lot of sense, actually.
It did dilute education a little - but that was because it needed it. The game gets more and more serious about needing to pay attention to education as it goes, which is a big part of how you are continuously challenged harder and harder to manage your nation properly as the game goes on. Still, this was all done because testing showed this dilution in the early game was necessary.
It also makes it more possible to strategically USE undereducation early on, but it does come with the penalty to your scientific achievement rate to do it. That said, you might be able to grow a lot faster and maybe in the long run get more from it once you've got a larger nation spread out. Now that food is more challenging, this is a very real possibility. And some players apparently feel it's worth focusing on other things than education early on so as to take advantage of the penalty limitations to allow them to turn their backs on that issue while they achieve other things for a while. Not a bad approach - not mine - but not a bad approach.
The point is always to try to design things so that indeed, there is no perfect way to play. And so that sometimes a negative can be harnessed to a greater positive if navigated properly, like how you CAN use severe crime levels to spawn barb criminals that you can build a large amount of captives to use as slaves with. Not necessarily an OPTIMAL strategy, but has its place if you're skilled enough to keep it from becoming a bigger problem than you can handle.
Even in the prehistoric, you ignore education at peril unless you are doing it with purpose. You WILL fall behind in research if you ignore it. The differences may not be too strong between positive and negative amounts but consider that the range is from -5% to 0 to +5% on numerous yields AND commerces. That's not a 5% difference, it's a 10% difference between high end and low end. 10% difference in the first era means a very large difference in how quickly you achieve techs and we all know how powerful it can be to get out ahead on techs, but not only that, the difference in production is profound, which is the speed to achieve units (largely for hunting, security, and managing your properties more effectively) and buildings that can mean even more production and research, faster, sooner, unlocking MORE access to MORE production and research faster and sooner. Many small things make for a very big thing ultimately.
The nice thing about a positive education strategy is that if you are watching your levels and understanding that you can't benefit from OVERdoing it, then you can effectively only control it as much as you need to to get the best benefit and don't waste by pushing harder to get a higher level, fighting decay to do it and costing you tons in unit upkeep. It's easy to make the mistake of spending too many resources on over-dedication to education, but should be fairly easy to ensure it's strong if you care to.