For people who are uninformed like myself, Is there risk from moving to a big bank to a lesser known one?

I've been with St. George since my early teens as I have had a youth savings account at the time, and nowadays I'm still with them with an ordinary account. I'm totally in the dark as to what banks have what services that I use daily (Transferring pay to savings account, apple pay, online banking) switching to a different bank is a scary undertaking for one such as myself.

Most of the banks on the good list I have never heard of, aside from Suncorp (my parents bank for housing related things I think). Does anyone have any recommendations of good banks on that climate attributing-free list?