how come? just the security aspect of it?
if it's not liking android or ios, there are some which you can run linux on.
Was around when phones became more than something doctors and executives had (possibly just installed in the car), was around during the doctors and executives time as well but was not paying much attention there. Cost was an issue but then pay as you go as it is known around here (you buy credit from shops). Did not like to be contactable when out and about and thus avoiding having one, or when I was compelled to it was a glorified house phone and spent its life tethered to the wall really. It befell an "accident" the very first car ride it could have as well when that ended.
Since then I still don't like to be contacted when out and about. Lack of devices I am free to do what I like with did put me off as well; I have less experience with the Linux side of things there (saw ubuntu were doing something but that was about it), was interested in de googled phones too*.
Equally I don't like having to have data run out each month (phone calls and SMS last in some things forever but in most for about a year which is fine).
Today I would also seek a phone that has a 3.5mm headphone, a SD card slot and while in the realm of fantasy a battery that can be easily removed and replaced (though I am prepared to compromise on that one and hack it in myself). Mind you I still don't care about being contacted when out and about.
Thus far in life the only problem I think I have had is I could not go to a concert for my favourite band the other year as they tried to sell tickets through a phone focused thing, the PC side did not work and when I pulled apart the application I thought I might as well package up my data and post it to ID theft boards myself as at least they would have the right name and address which stands a better chance of being removed from whatever list/loan application/... it ends up on rather than "sir, the computer has a different name here".
*others new to this then this guy has some interesting stuff
Short version. You sacrifice some minor abilities as far as google services wound into things, gain privacy options, gain more battery life, sacrifice less memory to stupid background processes and yeah. Can even still use a few google services as a genero user if you wanted.