The only answer that anyone here can give is: Maybe…
It may affect the site, and it may not. Pages are normaly thought of as “less efficient” tham posts, but that’s mainly for the admin area where the correct ordering and hierarchy needs to be established. When you’re just viewing a page that doesn’t really come into it.
The biggest thing that I can think of that would affect performamce is if you allow your site to automatically generate navigation menus from your pages, and you have that 3,500 menu items. That’s a lot of work for the server ot do, and could be a possible cause.
Of course, that’s all just guessing. There’s no way to possibly tell without knowing a whole lot more about how your site is set up.
