Actually, it really depends on the size of your group. I prefer either purchasing a Data SIM card (from Shopee) or an eSIM (via an app) over using a MiFi device.
MiFi may be cost-saving if your group stays together, but it becomes problematic when your group decides to split up or someone goes away for a toilet break.
Another option is to use a spare phone to run a hotspot only. It would usually last longer compared to hotspotting the internet on your primary phone. Anyway, it really depends on where you go; in some places, SIM cards with data are very affordable.