In my physical wallet I can take the card I use daily (which is on a limited account and no big deal if I lose it) and leave the others at home. On my phone, there are all the cards I ever used or plan to use at some point in the future.
[1] don't tell Mr. Fox he's running a business
[2] ... and will probably be adding a third
You may have multiple cards from the same bank (personal, family, business).
Different cash back from the same bank making you want to use one card over another.
Apparently an accessibility thing and maybe a wider standard than Mastercard. See image of cards near top of https://www.mastercard.com.au/en-au/personal/find-a-card/tou...