Is it necessary to get a 256 GB phone or is 128 GB enough?

I won't be changing it for at least 5 years. My current phone is from 2019 and it's starting to show it's age. I would leave it but I need to be able to use a phone with a functioning voice assistant because I depend on it sometimes.

I did get a new secondary phone with lower specs from Xiaomi but it has limited features and it's voice assistant never hears me in the street even if I yell at it, one time it hears me and 10 times it doesn't which is ridiculous. So I'm selling it and I will get a good phone to use as my main phone and my main phone will be my secondary.
I need 2 phones because I control the main one with the secondary with a Bluetooth mouse app when I'm in bed. I have a picture of my set up but I am nervous about sharing it anywhere.

So I can get a 128 gb phone or pay a bit more and get the 256 gb version of the same phone which I got in mind and be in a little debt with myself. There's a discount on the 128 one so I'm trying to come to a decision 🤔

Edit: No discount it was an old link.