Shawnbeleiu - I completely agree with and relate to everything you've said here.

Same situation for me as everyone here, accept my phone was a ZTE Blaze.
When I showed MetroPCS a virus file from my phone he said it was a paperweight now, that uninstalling and/or removing files, using safe mode, hard reset etc. are all pointless as virus goes all the way to a firmware/hardware level.

I got rid of my laptop, got a new phone, a new router twice & had Comcast out twice to improve router/network security. This was in November 2019. Took until May 2020 (6 months) for phone & the router internet/wifi to begin repeating same issues (no laptop currently).

I've dealt with this situation for years and my best advice to save aggravation, frustration and your sanity is don't try to 'fix' these issues when they occur to this severity & breadth, don't try to figure out who, what, why.
Just swap out phone, router & hard drives every six months or at 1st confirmation of hack.

Anything else is just pointlessly banging your head against a brick wall, while constantly being technically & personally exposed & vulnerable.