I do agree that the Sd card should have remained.
I personally choose not to use a Sd Card in my N20 Ultra 5G and instead bought0 the largest internal storage I can afford and use Samsung Cloud and Dropbox.
In my case I've had Sd cards fail and corrupting, and other issues as in the phone rejecting them.
I appreciate what your saying about the headphone 3.5mm jack and I remember many people raising an eyebrow when Apple removed this from their newest line of Apple iPhone's at the time.
As technology and hardware capabilities grows market trend is that people want more in their phone's so manufacturers have to find space inside to incorporate it all.
It seems the space that this jack took up has been used to accommodate this.
Maybe now manufacturers can find a way to make the hardware smaller so they can re introduce this ! Time and the next lines of models will tell.
Personally I've always used Bluetooth Headphones and earphones i.e Galaxy Buds and Galaxy Live and Bose Bluetooth Headphones, but I also appreciate people want to use their headphones and earphones of choice or prefer to use ones they've been using for a while as they like them and have in some cases invested quite a lot of money in them.
At least special dongle cords were introduced to allow people to continue to use theirs. I appreciate that means another bit to carry around and another connection between the headphones and phone which can cause some degradation in sound quality in some cases.
It's also good that Samsung try to make sure potential buyers of the phone's with no headphone 3.5mm jack option are aware of this before buying so they can make an informed choice whether to pull the trigger or not.
It's always advisable to perform some form of investigation homework on a phone before buying whether it be via a Google Search, the manufacturers website or YouTube reviews.
In my opinion Apple severely sandbox their hardware and iOS software on their products.
In this I mean they control quite a lot of what you can do which in some cases restricts the true power of their idevices.
Android being more open source opens very much more potential on Samsung phone's.
I remember when I ditched my iPhone's and bought a Samsung phone and was actually impressed that I could place my app icon where I wanted and not where Apple dictated they should go on their iPhone screen.
And that was the very tip of the iceberg on my journey on learning how powerful Samsung phone's are with Android Software.
I totally agree with @APARMAR comment on the soc that Samsung uses.
In my personal opinion the Snapdragon soc creates much better optimisation which means the phone handles better along with better battery output in my experience.
I returned the Uk version of the N20 Ultra 5G Exynos version and imported the Snapdragon version and the difference is night and day.
That said I've spoken to people who own Exynos models including family and their happy with their phone's.
No disrespect to anyone but it seems to be phone geeks like me and others on forums like this that typically know there can be a difference.
People usually realise this type of difference of soc when they are having some issues and start Google Searching or come to forums.
As Samsung has supplied phone's in the Uk with Snapdragon soc in them it should in my opinion be a choice at the point of sale which variant to go for.
I'm assuming as Samsung manufacturers the Exynos version it's a cost implication compared to the Snapdragon which Qualcomm manufacture.
From recent Internet chatter it seems the next variant of Exynos soc has been improved so time will tell on this one.
Current Phone > Samsung Z Fold³ 5G.
I think the latest Exynos processors provides a far better experience and the Snapdragon advantage is not so significant, though may still be 2nd best. According to these tests the Exynos performs relatively well. https://www.androidauthority.com/samsung-galaxy-s21-ultra-snapdragon-vs-exynos-1195066/
I have had the S21 Ultra Exynos for around three weeks and am pretty happy with the performance myself. Know the removal of the SD card slot and Headphone jack were not universally popular but there are workarounds. Not sure the jack will come back to the flagships (with Bluetooth being pretty popular), perhaps more of a chance with the SD card slot but maybe more likely there will be bigger internal storage options. I think Samsung still offers much more customisation and innovation.