Applying a blanket value to all silent films and all contemporary films will lead us to generalize to an absurd degree. There are certainly plenty of silent films that are better and more entertaining than some of the B movies that are being released today just as there are some high quality films being released today that are better than the worst silent films of the silent era.
If we ask "Are the best silent films better than today's best films?" we will still have a difficult task in making a comparison, but we'd have a better starting point, I think. My inclination, if this were the question, would be to say that today's films are better. This is just an opinion, however, based mostly on my own ideas of what is entertaining and not so much on the artistic qualities of cinematic works from the past or the present.
When we talk about the art of the cinema, it seems to me that movies are like paintings and, essentially, art is art and it doesn't get better it just expands.