As far as your wired earbuds, buy the Samsung USB-C to headphone jack adapter - I bought one for my wife and I from a local electronics store for about $10 usd.
You missed the lack of MST : )
I understand what you're saying here, but if you had known about the lack of features BEFORE (i.e. the research) , you could have picked an A71 or S10+ or Note 10
But yeah. Lesson learned. Next time I will not trust official information coming from Samsung and will check with third parties on Youtube.
a) The audio port has been missing since the Note 10 series, this is nothing new and is like this from MOST manufacturers from 2019 on.
b) What YOU expect to be present is nothing of their concern, again the Note 20 phone ditched the SD card (unless you bought the ultra) so a tiny bit of research would have been all you needed. The fact that they don't list this as not being there is laughable. They also dont list that it does not have a pencil sharpener, or a site to site transporter. No manufacturer in the world is going to list what they DONT have.
c) While I do not support their decision, they are not expecting you to use your laptop to charge your phone, they are assuming that you have a previous Samsung device, that you can use the charger from. and in your case, they are right. You can use the charger, and cable from your S8+ to charge your S21 Ultra.
d) The radio chip "that was removed years ago", is still present in the S21, S21+, and S21 Ultra.
I was expecting not to have a power adapter, disagree that decision but that was something I already knew because Samsung made a disclaimer months ago. So yes, manufacturers announce important changes when they ditch a basic feature.
About the assumption that I already have a power adapter, that is wrong. Following that line of thought and they will assume we already have a data cable so it can be ditched too. And hey, why not ditch the internal speaker? Everybody uses wireless earbuds. That is wrong.
And sorry to inform you but the S21 Ultra does not have radio chip. There is no FM tuner app and have tried to use other apps (old because this chip was ditched before the S8) and it does not work.
I am also a customer. I am not paid in any way by Samsung. Again, your statement is WRONG. There aren't many devices that are manufactured in 2021 with BOTH an SD card and a 3.5mm headphone jack. For a "most basic" feature, it sure is hard to find, huh? If it they are a must, perhaps you should have researched if it had these before purchase. It would have taken moments to research, the specs are listed right there on the Samsung website. A battery IS a requirement of the device, and IS listed in the specs.
It is not my assumption that you already have a power adapter, it is Samsung's, and, again, they were RIGHT in your case, as YOU DO HAVE ONE from your S8+. Again I stated that I do not agree with this, but, again, it was not MY decision. If you did not have one, they are happy to sell you one for $15 (the same price as the USB to Audio jack adapter BTW).
GSM Arena states that it does have the FM radio chip, as it likely does, but is likely not enabled for use, try installing a modern app to listen to it, like Next Radio, if it says you dont have in enabled then you may be right here, though the hardware IS there (and I enjoyed it on my S8+ by the way). Not having an app, or an older app not detecting it does not mean "the chip was ditched".
I found also the solution about NextRadio but the app says my FM is disabled and I need to ask my operator to disable it. I was reading that I can do thag but need to pay a fee, when I already pay for that chip be phisically in my phone. Samsung is making bad decisions.