I don't think twice about looking at Trek geometry on my phone.
If a brand sells in a physical store, I really don't care if their website isn't the easiest to use.
Now if a brand is DTC only and has a wonky or less than fully informative website?...well that is indefensible.
^ but this is website focused and not phone/computer based. I haven't ever been upset at my phone's lack of screen size when it comes to a website. If it's tough to view something, I don't get upset because it's like a 5" screen so of course some things are tough to view.