It's simply a good start for newer players. Once you really have an understanding of the game you start skipping Eurekahs because you know they deter you from the optimal path. But for newer players this is incredibly hard to determine. Fk, even for me it is incredibly hard to determine most of the time. Is it worth delaying Industrialization for 5 turns in order to get the Eurekah? IDK, I'm losing out on a lot of hammers for some science.. etc.
In the end, it might be optimal to purposefully ignore/miss a Eurekah to get a key tech, but this decision requires extensive knowledge of the game and its diverging paths!
The point of this approach is that if you try and get every Eurekah, new players will feel very fast that some Eurekahs are hard to get, some may slow them down, and honestly, which ones are easier/harder to get depends on your playstyle. So the idea is by focussing on Eurekahs/Inspos you get an instinctive, personal understanding of which one you deem essential and which ones you don't, instead of just copying/parroting what "better" players do, you feel me? Approaching Civ in this way is, imho, almost always better. Learning something by doing is more effective, helpful and more easily remembered than being told what to do
I feel like one of the things I have to overcome the most is that during my younger Civ days, I was overly attracted to build orders (think approximately Civ II). I had to get over those habits (still do - well, other habits, but still, playing Civ is about breaking habits). Civ is just really complicated, so it is really easy to latch on to the first thing that works and then get frustrated when that strategy no longer works for you (especially if you are playing on a lower difficulty, then try to move up to a higher one) instead of learning a new way. So I'm a bit hesitant whenever answers become really simple.
That said, the process that taught me the most about how to get the right "feel" for Civ 6 balance was to plan out the number of Districts I was going to build based on getting all the relevant Eurekas/Inspirations, and then improvising a strategy from the results of that play. Which, might be fun and informative to actually list out the process, now that I think about it. So:
"Okay, 1 District for State Workforce. 2 Campuses for Recorded History. 1 Encampment for Military Training. 3 Trade Route Districts for Guilds, 2 of them have to be Commercial Hubs. 2 Holy Sites for Divine Right. At least one Theater Square for Humanism and Natural History."
"But if I'm going for a Culture Victory, do I need 2 Campuses that early?"
"Is it really worth delaying Exploration so I can finish my Markets?"
"I definitely don't think it is worth building Holy Sites just to get the boost for Divine Right."
"It turns out I actually need to build a fair amount of Theater Squares to get an Artist before I hit Humanism in my Science Victory. Is it really worth it, or should I just focus on my Science?"
"Ok, I see that it may not be necessary to get these particular Inspirations, but it is pretty clear the game expects you to have about 2 Campuses, a Wonder, a Theater Square, and 4 trade routes by this point in the game. That gives me a good guideline to evaluate the pace of my play."
So yes, In short, "I feel ya, man"
