Are you short of space on your phone? As a "uber-paranoid privacy nut" why wouldn't you keep it installed and continue to message those two contacts securely?
1) Both of those contacts are not "uber-paranoid privacy nuts" so they will be dropping Signal too for the same reason.
2) The inconvenience factor. I don't really like smart phones and would live without one if I didn't need one for very specific purposes. Being able to text close family and friends is one of those specific purposes. I have zero interest in having to juggle different text-ing apps for different contacts.
I should also add that I'm way more concerned about
a) spyware that comes pre-installed with phones that sends data to 3rd parties that have bought it
b) malware (I don't install many apps for this reason, and I like to use FOSS software for the same reason)
b) being in control of a device that I own (same reason I use Linux on my desktops and laptops)
I'm less concerned about SMS messages being intercepted, except for things like MFA codes. So of all the "contacts" that I would like to use Signal, it would be situations where the content is security-sensitive, which [unfortunately] currently accounts for virtually 0% of e2e encrypted messages coming into Signal.
