Not necessarily; I fired up some old devices last month, and the way their bitmap icons and apps and screens appeared, can only be defined as "Crips" and "Sharp". I'm not saying prettily or beneficially so! But they were definitely very stark and constrasty (let alone colourful and "stand-out-ish"!) holding them next to my modern phone or PC.

I don't think "Vector vs bitmap" is necessarily the cause - more of design sensibility. When I look at the lineup of google apps on my phone which all look EXACTLY the same (3 primary colours in random rotation; I can only effectively use / distinguish them if I memorize location of icon), and then the same as slack and my son's daycare app which also use swirls of same 3 primary colours; and when I compare my Windows desktop and icons and browsers to old apps - there's a definite brutal sharpness to old stuff.