I saw no numbers on any of the icons when I visited in my web browser.

It looks like they have a deficient web page design that doesn’t work well on mobile. Thus leading to a much more confusing interface.

It's not for you, obviously. It's for academics and nerds that are interested in these kinds of data sets and used to have much more trouble finding and consuming them.

I think if they had a better web page interface, then a lot more people would be able to make use of the site.

And I think that would probably also serve the professional astronomers or astronomical researchers better.

To put it nicely: you're not the target audience. This is the astronomy equivalent of the $50000/yr bespoke mechanical engineering simulator. This is not an outreach tool (or a citizen science tool). You don't take this to a dark field with a telescope at night (it's not a skymap), this will be used on a big screen to plan observations, or at an observatory (where you'll have at least 3 screens running). These kind of applications are developed with deep and continuous input from their users, and there's nothing superfluous there.

What do you even mean by "better"?

Who is it that can manage the niche software needed to digest the data sets but have such trouble figuring out how to navigate that web page? Of what use would they be to the academics and weird nerds?

It took me less than two minutes to figure out navigation and how the menu works. If you really want to make an impression in this area it would probably be better to spend time on improving VO-software and organising study groups where you live.