In my world too but most smartphones sold these days in fact do not have removable batteries by design. You don't know this?
>Buying a new (crappy, what do you expect for 50 Dollars?) phone because your perfectly working one isn't supported anymore is NOT satisfying and not a solution
That $50 phone is just as good or better than a phone sold 3 or 4 years ago.
>I feel that you're a bit lost. You want to save a bit of money
No dude... I buy a new phone every two years to have a faster one, better features (camera), and better security features (fingerprint reader). Lucky me, I can afford it. My secondary phone is a 2 1/2 year old Nexus 5 which still gets security updates and will for many more years via custom ROMs. Security updates were not the reason I bought a new phone.
Sorry, you don't really seem to be up on current smartphone technology to comment on this intelligently but philosophically I do agree with you.