I have become convinced in a lot of cases express suburban trains are less useful that they sound. It’s like vibes-based service planning. It feels faster as an “express” but the reality of fitting it between all stations services (plus any track or station limitations) means it actually isn’t much.
On weekdays they run a real express service and also the issue here is not offering a meaningful choice of departure and arrival times.
I was speaking rather generally. There are some express suburban trains in Australia that are less useful. This would also be the case here in North America if/when we start running our trains several times an hour. At decent frequencies, an express would end of catching up with the local in front.