Maybe a daring comparison since I'm not the best Civ 6 player.. But ig most of the ppl here played it at least once so I'll just do it.
Playing without a specific BuildOrder (speaking of a high ranked one -> Implementing specific reclaim to specific times to get the optimal balance in the first 2-3 minutes) feels like sending the first settler to a suboptimal place where you wanna start your city. Even though in 30 rounds it doesn't matter that your opponent had like 2 food and 1 production more than you simply cuz the decisions overtime have more weight, but it just feels like you're already behind and have to actively close that gap.
Back to FAF I personally distinguish between decisions and BOs. E.g. against Harzer on Cobalt I went for engi - lab - scout - engi - lab - scout ; both of my labs got shot down without killing an engineer and in addition to that two of my engis died. From that point it was basically gg. But those are the decisions and not the point I'm trying to make, that's purely "skill issue" and I accept it.
Taking Open Palms for example. I had huge struggles with that map where I didn't look for a specific Buildorder. I went for a basic one and got fucked everytime. iirc I have 7 games played on that and won 0 out of them, only exception being a win against Harzer after he showed me a buildorder (nice coincidence, right?). And that's the main part I'm trying to make but which is just being commented with "skill issue". Not only knowing where to send the engis but also knowing how much mass you need is a critical factor. e.g. if you don't know one engi getting the rocks is enough to support quite a lot of factories, you'll most likely expand with two at the same time bc that's what you usually do to grab mexes for that mass. Since labs are a big thing on Open Palms however you'd need to defend those very early expanding engis with two tanks making it a huge investment. If your opponent knows one engi is enough, he basically saves one tank and gets additional buildpower to get his facs out and also gets things like a bomber way earlier -> It's an advantage on his side.
That's basically the whole point I'm trying to make, not sure if OpenPalms is the best option but since it's a known map I went for that one. If you're like "reee learn how to read maps with reclaim" or "skill issue", then congratz. Thanks for you comment which doesn't change anything. Clown.
Also that's where Yps' point had a lot of impact. Simply bc I had the feeling that I'm at least equal then, I ended up playing more aggressively and won after getting killed by some random 1500s in ladder (even though it was a while ago). So yeah, think that has a shit ton of impact.
And if someone comes up with "A BO is not necessary, play that map 10 times and you know how much you can afford with the reclaim", that's literally what a BO means for me. The awareness of what you can afford based on the map / reclaim bc you know "okay I have to send one engi there to not stall, I can keep that one in my base, [...]" is my definition of getting a BO even though it wasn't whored in sandbox.