Note: Question is SPECIFICALLY to experienced day traders who have been day trading for several years and spend AT LEAST four hours a day trading.
If you're day trading full time and you have all the time in the world for it...and you can only choose one of those devices, which would you choose...and most importantly, why that one instead of the others?
I am much comfortable to use laptop or desktop, though I am not saying that mobile is not a good thing to use to trade cryptocurrency.
Although, using mobile phone only is good is when you are outside your home or your in province, in which mobile advantage is much more advantage only due to it is portable. But this was just my own opinion only.
I also use my laptop for multi time frame analysis because of its large screen, to determine the main or minor trends, support and resistance, demand and supply zones, fortunately the indicators used in my trading strategy is the default type, thus I had the same on my mobile phone trading chart, I was able to transfer those information to my mobile phone so that I can easily place a trade anywhere, in a nutshell I used both devices for my day trading, meanwhile some traders might be comfortable with mobile phones, I believe majority traders will use desktop or laptops.