ok. so here's the thing. i feel like this thought experiment can be resolved if you just use some of you immense wealth to buy some stilts or something. like a snail is essentially a dalek, they're not going to easily get to you when you're elevated.

in a more philosophical answer, immortality sounds awful. the beauty of life is found in the things that are ephemeral or the things that feel eternal to when our lives are relatively short. i'd rather at least make friends with the snail so i could have one companion i didn't have to watch age and fade away. also, snails are lowkey kinda cute.