Just to be clear, my intent was never to undersell P2W. I did say that they are a big deal (maybe I should have said that at the beginning instead of the middle of my post), I'm only pushing back against the idea that owning a P2W is more important than building out your grid, which I think is incorrect. And you are right, they're not mutually exclusive but synergistic, so doing both will get you really OP.
That is true from both directions though: having a P2W does not diminish the value of your grid, on the contrary, it is further boosted by FLB-ing your grid.
And you will get your MLB guardian eido - think of it as practice for T4 soul grind
I haven't done the math as it's too dependent on your team setup and grid, but I think the power difference between guardian eido and P2W may be comparable to the power difference between f2p full FLB and spacewhale full FLB.
It's sort of a continuum though. I mean one brick per tower isn't crazy for most ppl 'cos of the ranking rewards, so most of us can FLB 2 hime weapons per year naturally. If you go full mono-element, you can mtix for weapon dupes once you have your core team and buy those brick deals on top of what we get from tower - it'll add up to several hundred dollars or so a year if you buy all the bricks and mtix, which is admittedly a lot for a video game, but a lot of ppl probably spend more eating out than that over a year and spend even more on other luxury items like fancy cars and lavish vacations (at least that's how I justify spending on video games to myself.) It's only spacewhale territory if you try to do this for more than one element.
In any case. it's often the same type of considerations whether you're using f2p or not anyway - with light for example, ppl often go for dupe Tish lances for the exceed regardless of whether they're building a lance grid or not; f2p FLB grid will also need exceed, but you'll get it from UE axe or guardian glaive instead.
I actually never really took issue with what you include/exclude since honestly I haven't even been around long enough to have a right to comment
These are the kinda statements that I'm pushing back against. I actually do NOT befriend low rank players anymore regardless of what eidos they have (before or after I got fluffy) 'cos they mess up my rags too often (if you're already on my friend list you're safe, 'cos i have a no-kick policy unless you go inactive or stuff your eido slots with lilims or kaisers.) Vets with no P2W but are in strong unions are very valuable as they give me access to their raids. I mean, I still need a large number of friends with fluffy, but it doesn't have to be my entire friend list.
Also, I've been clearing content just fine well before I got fluffy - 20/20 mission points for every GO, AAB all ults and all AQ5. I like to think that some noob with a P2W can't accomplish that and I'm not even technically a vet (played for almost a year at this point.) P2W eidos are OP, but they're not going to solve everything.
I do agree about the alienating ppl part though, I kinda wish they designed things such that the optimal eido combo is 1 P2W and 1 F2P like the guardian eido so you have an incentive to befriend ppl with something you don't have (kinda like Dia U - you don't really want to befriend other Dia U but other elemental P2W, if only Dia U wasn't also P2W.)
Main eido selection is a small part of the number of decisions you have to make regarding equipment though. Hime, weapons and sub-eido selections are largely independent of the main eido selection.