Since I do not want a fight over this question, I wanted to state from the beginning, I think we all agree that it should be decided according to different product requirements.(?)
However, in such discussions, we need to consider those who use the product rather than the developers. I always take a look at the data outputs while making such decisions.
Regarding to perficient.com, at 2020, based on 30.02 trillion visits, 68% of users were browsing from their mobile phones but less than half the average time they spend per visit, according to desktop users.
This may because of several reasons, one is most of desktop users are more likely to spend time on their computers of course. On the other hand, we should also consider that most of websites are not REALLY optimized for mobile users so, this may cause users not to prefer to browse the site anymore.
It is always necessary to speed up and optimize any user experience;
In 1979, Walter J. Doherty (IBM Researcher) mentioned that
user experience turns from painful to addictive after the system feedback time drops below 400ms.”
and they call it Doherty Threshold.
We are not here to understand whether its true or not, the thing is response time has a large amount of importance while we use “computer”.
My personal idea is to start with mobile design, and be minimalist.
I did not arrive at this conclusion solely for the reasons I have stated here. I always take note of the applications whose UI designs I like on websites, mobile applications and desktop applications. What they all have in common is that they are extremely simple and useful.
First of all, we shouldn't consider the question of usability about which design we should base on because you can create a lousy user experience no matter which one you start with.
But minimal animation also brings maximum response time, and if you start with mobile design, you inadvertently fit those requirements just a little bit more.
In addition, you can present the contents that you fit on small screens (if you can) to the user in a more comfortable way as the screen expands.
I'm not a UI designer, but I see a lot of designers give priority to mobile design these days.
In fact, you can come across this while browsing websites where you can buy many templates, most of them put mobile application images at the beginning.
It is of course debatable whether this decision is due to the fact that the demand is mostly in mobile designs or that the designers can express themselves better in mobile design.
Which one you go first?