I had long discussions over whether we could just not use tons on npm libraries and use the native browser feature for things like that. I typically lose these discussions because I'm considered the backend guy. My knowledge about HTML, JS and CSS dates back to times when there was no npm...
People often forget how good tablet and mobile datepickers have gotten as well. They may not match your sites weird style exactly, but they'll feel native and handle lots of things like ADA compliance that your crappy custom one likely won't.
"you're" here referring to higher ups not you personally