Accessibility of Vanguard's site

I am wondering if anyone uses Vanguard for their retirement plan or personal investments and, if so, your sense of accessibility of their site.
Personally, I have been a Vanguard user for several years and, as time has passed, I have found their accessibility deteriorating significantly. On the Mac side, the issues are much worse than on their IOS app. I find navigation very difficult, buttons mislabeled, interactions with dialogues and lists don't work, etc.
I have spoken with a customer representative and, despite trying for several months, I cannot determine whether Vanguard has anyone dedicated to accessibility of their site. I know they used to have such a group, but the rep can't find anything about them. I'd like more evidence (whether I'm right or wrong) from this great group of users) so I can advise Vanguard. Sad truth, in my opinion, Vanguard offers great products but I want accessibility to work well so I can use the site easily.
Thanks for any information you can provide.