You are asking a meaningless question in order to promote, brag, justify and make public your own know-how having already accepted and understood whatever limitations in order to justify your own choice.

The point of a rasperri PI is to allow general, easy, and intentional bespoke availability of a fully programmable platform, where it also allows you access to low level, but practical means of acheiving home automation via GPIO etc.

I have 5 old phones in my cupboard, the most recent 3 of them have locked bootloaders and could potentially be rooted simply because of them not being region locked, while not gauranteeing me any real and complete support such as a PI would.

Nevermind even thinking as far ahead as GPIO pins etc etc.

At best, 1 out of the 5 phones might be able to eventually, and with effort/time and possible additional cost for extras give me parity to a PI, even exceeed the PI in compute.

But that is not the point. You know it. I know it.

Your post is not in search of an answer. You know the answer, you are the minority, and you know this.

You would not get an expensive PI if you had what you need from your old phone and skillz.

So why ask us where you already knew the answer...

It's because you are not asking anything, you are trying to show off and be dishonest by posing it as a question while assuming generousity by 'helping' people not 'waste money'

You are transparent buddy.

Yep, the typos are understood and left as is. Does nothing to take away my meaning.