It seems like cost and fear of loss/damage is your main fear. No arguing with that.
I'm very intentional with my smartphone. It's my tool, I am in charge of it rather than the other way round. I have to have one (live abroad thousands of miles from family, young children, DH travels a lot for work, elderly parents etc) but I'm not its gimp.
It's possible for smartphones to enhance your life with minimal thought. It's a mindset. There's nothing more/less addictive about a smartphone than alcohol, say - you can have a glass on a Saturday night easily enough, not everyone becomes an alcoholic. I don't have any of the Facebook or Instagram or TikTok platforms as I realised from the outset that they're nothing more than advertising platforms and they are built (like tobacco products for example) specifically to become addictive.
All in all, a smartphone makes my life easier: I have maps in my pocket, a phone to make and receive calls and texts across time zones, vouchers and coupons, I can pay for parking, a camera at all times, I can pay for things in shops without ensuring I have the right cash or cards. I use it when I need it, it doesn't have a hold over me. I have a phone case and a screen protector and don't fear damage. It's in my bag so unless I lose my bag I won't lose it (and if I lose my bag there are more troublesome things to worry about). Maybe consider it. It needn't be a bad thing.