2.4 kg isn't heavy though. I agree from 3kg onwards it can be a little tough, but in my opinion a laptop between 2 and 3kg (maybe 3.5kg with the charger) is perfectly fine.
If you ask me it depends on how much you travel with the laptop. Unless you do it A LOT (like daily) there's not much reason to get an ultrabook in my opinion, as a regular 13'+ inch laptop will do just fine provided it has at least some sort of GPU, even base Vega graphics. Why would you need an extra keyboard for your laptop, by the way?
But a "top 10 laptop" list doesn't have to be swarming with ultrabooks with one or maybe two gaming laptops thrown in the mix. ThinkPad P53 is surely far better than any ultrabook in performance, durability, keyboard and screen options.
Also, I really like the $200 PineBook Pro - very cheap, good screen, okay specs for its price, huge battery life from what I've seen of it. I'm waiting for it to get released and receive more tests. Maybe Linus will feature it on his channel