Question about Dell S2722DC

Yes, all USB connections can be used together. However, I wouldn't choose a 2560 x 1440 pixel resolution for a 27-inch screen, because there are already 4K UHD 3840 x 2160 pixel screens available from 350 francs. In Windows 10 or MacOS, you can adjust the scaling and small fonts will appear larger. The huge advantage of 3840 x 2160 is that even if you set this picture to 150% scaling and use it as a 2560 x 1440 pixel display, the fonts are now all razor-sharp, even small fonts, because there are more pixels available. A 4KUHD Montor from 350 francs that also has USB-C would be this model, for example:

LG 27UK670-B (3840 x 2160 Pixels, 27 ")

There are even some from 350 with 32 inches, where you could even use the full 3840 x 2160 pixel resolution without scaling:

Samsung LS32AM700URXEN (3840 x 2160 Pixels, 32 ")