Put the money you would have spent buying outright in a savings account yielding 4%.
Tons and tons of people have their cash sitting in a shitty Chase savings account yielding 0.1%, while there are many FDIC insured banks offering at least 3% and up to 5%. As a critical mass of these people realize the options available, they'll rapidly move their money with online transfers causing more banks to collapse. The extremely rapid outflows are what killed SVB, Signature, and Republic who were screwed because they had too many low yielding treasuries because the Fed hiked rates so fast.
I've been yielding over 3% in a Capital One savings account since last year.
They can be purchased quite easily from the US treasury website, or investment sites like Fidelity.
I would not even be bothered to go through the financing hassle for the few tens of $ of interest that would yield.
As far as effort, if it's a high-yield savings account you should be getting one of those anyway, and then the phone-specific effort is a single transfer or doing nothing at all. And the financing itself is probably negligible.
If we were talking a car I would've agreed with you but I'd rather pay upfront for such smaller sums and get on with it.
I'm probably in the market for a new phone this year, and I'd absolutely do the 0% 24-month financing even for a "normal" priced phone. I get that some people are debt-averse, and I understand why, but if you can afford to pay for this phone outright, shying away from the financing plan is irrational.
I couldn't imagine financing a phone