You are correct the 4G is confining these days -- and that 128 G SSD will likely fill up sooner rather than later. There are two memory sockets - you can add another module easily. [URL]  
I just(as in i literally received it yesterday) purchased the Dell Inspiron 3511 (i3, 4GB ram, 128GB SSD) for my girlfriend. It was on sale and i know she doesn't need the best computer in the world. But futzing around with it today and looking at the performance i saw that her RAM was at 70-80% capacity at all times. Just idling doing nothing. BRAND NEW computer. nothing installed except Chrome.   Then it hit me, is 4GB just not enough at all for even basic stuff in 2021? Seemed like even just the basic windows stuff takes about that, 3GB of memory at all times. 3 out of 4 is pretty darn alarming. Tho 3 out of 8 would be much better..   And then another question, could i myself just change the RAM stick? put an 8GB stick instead of her 4? How complex is it?
Is 4GB of RAM just not enough nowadays? Inspiron 3511