Also, the on-going costs of a satellite phone are fairly high. The ham radio and SSB radio don't really have much in the way of costs, outside of the initial investment in equipment.
I agree. We rented an Iridium phone for our last voyage and also bought a "like new" (and it really was) Icom IC718 with tuner and antenna which I installed myself.
The Iridium cost us (rental and calls) about US$1800 for the voyage and we had to give it back. The entire radio setup cost about US$1100 and we still have it
And the other point is also really valid. When you are 2500 miles from land and something serious goes wrong, try switching on the Iridium and shouting into it "CALLING ALL SHIPS"
Or try to get daily weather advice.
I'd like to have an Iridium on board but there is no way I'd swap it for my SSB.