I have used it to great success, and often return to it while having issues with productivity. I find it best when my internal thoughts are troubled. Handing over control of when to work/when to rest to an external resource is usually enough of a lightened burden to get started. For a while I used it every day, but now I only use it when I find myself procrastinating or stuck in a rut.
I really enjoy using it as a browser plugin, bc you can configure most of them to also block distracting sites, and offer some level of "do you want to quit?" which is more of an emotional appear than a text editor gives me when editing etc/hosts.
I agree the 25min time is short for deep work. Usually a I do 1-2 25min periods to warm up, a 40min period of longer work, and then ramp it up to 1 or 2 90min periods with 10-20min breaks. When I go over 90min periods, I find I'm burnt out before the period ends and end up wasting time waiting for my break. Also I find I only get 5 or 6 periods of any length before I'm burnt out enough that a longer break is required.
Also that 5min period of rest may seem like not much, but if the work is overall interesting you will find yourself returning with a renewed vigor due to delayed gratification. Its a little jolt that can lengthen an overall work period making the breaks quickly pay for themselves.
I do find it clashes when you have external distractions like a spouse or animal. They don't understand the flow, and will expect you to break whenever, which can throw you out of the rhythm.
Overall using pomodoro allows you to think about one less thing and devote more energy to what matters. And if you are prone to procrastination/distraction that one thing can actually be pretty big.