Normal relays use a silver alloy not tungsten that is commonly used on ignition points. Some small signal relays use gold plated contacts.

It is desirable for silver contacts to have some pitting as arcing during operation prevents buildup of tarnish / plastic out gassing that will coat the contacts. In systems that have very low currents / voltage relative to contact size, tarnish builds as an insulator causing erratic operation.

To get past tarnish / coating issues, relays used in small signal applications have thin contacts that form an X . ( one contact is / the other \ and when they touch they form a X . ) This small contact area allows for some arcing to keep things conductive.

Sure, a regular relay will " work " for a while but it will become intermittent on operation. Thankfully, small signal relays are mostly used in industrial controls not cars.