Constructive criticism, open debate, grown up behaviour, and the dreaded FEL mode.

[TRS-80]

Yes, I would agree that comparing PinePhone with current Android / iOS offerings (on strictly functional basis anyway) will of course be unfavorable.

But I think you rather miss the point, which is to jump start a completely new platform (GNU/Linux phones) against a couple of very large and well entrenched incumbents who have had a decade+ long multi-million (billion?) dollar head start.

Of course there have been a number of attempts at GNU/Linux phones before, and to study these and see why they did not succeed I think is illuminating.  One such overview can be found here for instance.

At this point you could debate strategy, compare PinePhone approach (~ "get a lot of inexpensive units out there into hackers hands to get the ecosystem going") vs. Librem for example who chose a more expensive, powerful (and arguable more open) SoC (iMX6/8) but then spent years getting it well supported in Linux (and who are just now starting to ship in numbers).  Both projects have (more or less) the same end goal mind you: which is to produce a GNU/Linux phone, they are just taking different approaches.

The excitement you see all around here is because we have a real chance at making a real GNU/Linux phone once again, and for a lot of reasons many people (including myself, and many others who were around for previous attempts) feel this one has legs.  Current incumbents, while technically far ahead, have a very bad record in the areas of privacy and platform control, which is another big thing driving this.  And on these fronts (as well as some others) PinePhone far outshines them.

For me personally, I am absolutely delighted to have an option that is not Google nor iOS simply to be able to get off their respective plantations (so to speak), even with the current rough state of affairs (which as you even point out, is improving all the time).

BTW if you are not familiar with the concept of Free Software already, I invite you to check out that link in my signature for some additional perspective in this area.

FEL mode, AFAIU is some older and less well supported mode for booting that is no longer used because we have better options now in Linux with device trees, u-boot, etc.

I believe it's quite difficult to put together a smartphone with open enough hardware (as opposed to locked in hardware you would find in any cheap smartphone) that is well known and supported, but a lot of other people with more insights have written about this already

Almost impossible in fact.  See also Nicole Faerber (Librem CTO) talk at 2019 CCC about exactly these issues.  Do note that they were like 2 years into development already at that point.