Smoothness is mostly due to track quality, and is a practical result of design for high-speed running.
At least in Germany WiFi sucks and is not available everywhere – and even if it is you have to be lucky and actually be in a train that supports it. In general seats are most definitely more comfortable in longer distance trains. Yeah, you can find a seat that’s less comfortable in a long distance train than in a regional train, sure, but that’s hardly the point, is it?!
And electrical outlets are getting more common, sure, but the vast majority of German regional trains does not have them and you can only be certain that there will one in a high speed train.
WiFi varies a lot from country to country — some places you're lucky to get it on any train, others it's becoming coming common on even regional trains; seats on a lot of the older ICE2 sets were really quite terrible prior to their recent refurbishment, and a lot of IC trains in Germany had far better seats; electrical outlets differ from place to place — the TGV Duplex will never have power outlets at all seats, for example, despite being a high speed train, as there simply isn't sufficient power spare to provide them, and as another example in the UK it depends far more on rolling stock age (or refurbishment date) than whether it's a long-distance train or not.
The problem with the images of the Hyperloop interior is that it looks very much unlike anything you currently find in trains. It looks more like the inside of a race car – with a belt and all – and it doesn’t look like you are supposed to get up and walk around. It doesn’t seem as though there is enough space for that. Maybe that’s just some designer having an unnecessary flight of fancy (but that doesn’t exactly inspire confidence in the design if it’s that badly though out), maybe that’s an inherent downside of the design. Either way, not good.