I think I'm too clumsy for a programme like this

If you can tolerate an older phone by 2 or 3 generations, a cost-benefit analysis reveals its cheaper still to go used and buy that class on a Facebook marketplace like platform and then repeat that (selling or even keeping your old phone) when you're ready to upgrade again.

This is what I personally do. I haven't upgraded my iPhone 12 yet and when I do, I'll likely go like an iPhone at base settings thats 2-3 generations older than present then.

The final “Upgrade” is to wholly and completely acknowledge that you don’t own your hardware, we do. Frankly, leasing a modern Apple product feels more honest having everything locked down on a device I ostensibly “own” and while the OS constantly promotes their cloud & services ecosystem.