How does one minimalize privacy concerns on SIM cards and phone numbers

I’ve looked into VoIP numbers before, such as JMP chat as it it is one of the few if not the only one that can be used outside of US or Canada among privacy VoIP providers(MySudo, Cloaked etc.). But I will still need mobile data and any plans less than 30GB just doesn’t cut it, so I’m still forced to use my local ISP where they provide loads of data.

My thought was to get a VoIP number from JMP(hopefully it works it course), and register all the services that needs a phone number to work. And use a register a new SIM to disconnect my old phone number to only use it for mobile data.

But I wonder if using the VoIP to register the services, wouldn’t that just tie my identity to this other phone number anyways, since some services have KYC(although I am trying to register another account without the KYC part since it is only for specific service they provide aside from their main service)

Help me understand this a little about alias phone numbers. Thank you!