In my opinion, Dolphin is a filemanager.
It is a specialized file manager that supports only navigational mode. Similar to Krusader that supports only panel mode. This is unlike Konqueror in KDE3 which is universal.
over here it works. Strange, huh?
In KDE from 4.0 to 4.6 it did not work. Maybe they fixed it since.
or other systems, like Yast to bring up full functionality.
KDE4 also needs either Yast of NM. NM is not part of KDE4.
If KDE3 is not able to deliver a network interface so that I can set up my connection, it is a FAIL. Thats it. It fails.
Can KDE4 or Gnome deliver it without NM or Yast?
KDE3 depends on a package named smpppd.
smpppd is in no way needed to set up internet connection. It is completely not necessary. It is used only by kinternet to quickly control the connection from a non-administrative account. KDE4’s qinternet also depents on this package so there is no difference with KDE3 here.
Which is not installed by default, when you install KDE3.
This just means that you did not install KDE3 completely because kinternet depends on smpppd. If you had installed kinternet you would have smpppd installed.
If you installed KDE3 from a LiveDVD such as this you would have kinternet installed by default.
but it is time to move on.
Who should move on and where?
KDE4 is superior in all terms of usability it has more functions, is easier to use and so on. So riding Networkmanager to death in this discussion should lead to… what, exactly?
Can KDE4 connect Wi-Fi without NetworkManager or Yast/ifup?
You obviously need to because KDE3 can not deliver essential functionality and therefore you need a second DE.
You probably know better than me? 
So your statement tells the world, that you had some problems… for sure, its also KDE4�s fault.
I never used KDE4 so this is for sure not related to KDE4
Those times back I used Gnome.
I bet, you also did not test KDE4 in its latest version
Why if I know they did not implement the functionality I need and appearance I like?
Anyway I tried to logon in a KDE4.6 session but spotted that the bottom border of all menus remains on the screen even after menu disappears. I do not consider a DE that has such huge artifacts in any sense usable. Although the KDE4 devs will for sure blame Xorg or the video drivers.
slow (it is fast), uses a lot of resources
Well I do not insist it is slow. I have enough powerful desktop to not to bother about such things.
3 years ago it was like that, and I did not look at it recently so it still must be the same
I looked at it this summer at version 4.3 and also briefly at 4.6. I spotted no changes other than a new menu border bug which was not present in 4.3. Anyway you are right, screenshots are enough for me to conclude that I do not like it.
leaving old stuff behind to develop new stuff
…a tactic which leads to vibrations around zero point
to get new stuff better, faster and more reliable than old stuff.
If it was better and more reliable we would not use KDE3 still.