The more you browse, the more HTML nodes are drawn and for every change of the layout, it has to redraw everything, even invisible stuff.

There are style recalculations and other invisible things that consume CPU and Memory. You can open the performance monitor to see how it scales Performance monitor panel  |  Chrome DevTools  |  Chrome for Developers

Thats a downside of bubble SPA apps because they only add nodes to the entire layout and hide them, but not remove them if they are not visible