Why does a coffee pad machine make such a smooth delicious coffee?

In an amateur capacity I have been interested in (as everyone here surely is also) trying to make the perfect cup of coffee/espresso. I have tried all kinds of coffee making process, Moka pot coffee, espresso machines, drip coffee, French press. As well as trying various professional barista type establishments.

I quite accidentally discovered coffee pad machines, such as the one made by Senseo:

And it, to my taste, produces the smoothest least sour/bitter coffee I have tasted.

My question is: Why?
I am curious as to the chemical and physical processes that make coffee prepared in this way so smooth. I realise this is of course subjective. My own pallet comes into play, the type of coffee pads I use and so on.

Another question: Is this a “true” espresso?
It seems unlikely to me that these types of machine can produce the types of pressure seen in the more traditional espresso machines. It produces a crema, but I suspect that this is artificial from aeration, similar to how some of the cheaper espresso basket systems have an actual aerator in the basket to produce the appearance of a crema.

Has anyone had a similar reaction to this type of coffee preparation method? I find it some what ironic that with all the science that goes into coffee preparation — especially in the context of espresso — that this simple thing — for me — makes the best cup of coffee