Forex indeed consume less data, heck I can even see it from their UI that often outdated and often resemble an old computer terminal.
Just how after years of making big profit these forex company don't even want to put an effort into making a better UI is beyond me.
Good thing at least many exchanges will come to the rescue so I can trade forex with better UI.
Sometimes it could be a strategy to keep the user at home. I mean, yeah better user interface does help and everything evolves, but I've noticed it does feel odd sometimes when you visit a website, for example, that has updated itself.
You don't feel the same way as you did before the update. One odd example is Stake Casino, they constantly change the look and makes subtle changes like changing the VIP icon and all that. They might feel they are improving the user experinece but as someone who is using the site for years, I find it odd and somehow not so worthy.
One reason I find crypto trading way better than forex is that the government is not so involved. Yeah, most exchanges require KYC but there are ways to bypass it. Some countries have absurd taxes on trading profits.