Do yourself a favor and listen to those two podcasts I posted. The snapchat thief speaks specifically to the issue of someones ability to sim swap and potentially gain access to any and every login and password you have on your phone. The iron clad resolutions to protecting against this fully are mind blowingly difficult like a different email and password for EVERY saved account, never linking your banking to your phone, and so on.
I recently swapped phones and use to have EVERYTHING on my phone. When I setup the new phone I purposely did not connect all the accounts and copy over everything to the new phone but kept the old phone, with no sim, and have access to all the accounts, app logins and so on on the old phone (via wifi only). If anything like a sim swap ever were to happen the critical accounts would not be accessible.
The scary part is large balance accounts that are not FDIC protected or protected by other means. Even with FDIC its a nightmare but at least you'll get your funds back. The balances above 250k.. yeek.