This entirely depends on where you live and how fit you are. If you live at elevation and do a lot of climbing, sure then a 30t might be a good idea.
If you’re >4watt/kg and live in a flat area 36t is certainly a good fit, maybe even a 38t. I personally hardly use the 50t on the back and run a 36t year round. The steep climbs I have around me is short enough that you just power through them.