A good singer uses the whole body to sing, to a certain extent. You use your diaphragm to breathe and the sound is propelled out through your throat and your mouth. The shape of your mouth affects the sound. The size of your voicebox (which you have no control over) affects your voice, too.
I took voice lessons for years. They always told me all of this technical stuff that I understood in theory but not in practice, and it took me a long time to get where I am now. I used to sing more on my throat with very little breath support (not using the diaphragm) because I really didn't understand how to make it work. I would get very nervous when I sung, and then what little breath support I had would go right out the window.
Then I finally got a good teacher that got through my thick skull
Basically, what I thought of as "shouting" was singing. When you think about it, singing is sustained shouting. NOTE that I don't mean SCREAMING, that is bad for your voice. Just a regular yell or shout. Prepare to yell or shout, and what do you automatically do? You take a big breath! The trick is to learn how to keep using the breath longer and longer and not have to keep taking more at inappropriate times, and be able to adjust your volume without using up all of your breath. That one I am still working on. It takes lots of practice that I am very bad at (like playing scales on the piano to limber up your fingers). So I just do what I can.
The better you get at the breathing part, the longer you will be able to sing and the less tired your voice will get. Singing on your throat or in a breathy way is bad for your throat and you could get vocal nodes. The reason many pop and rock singers can't sing years well later is because they smoke, drink, & take drugs, or they are singing on their throat, or they tire out their voice by singing too long and not really knowing how to take care of it...theya re not "trained" for the most part.
Natural aging will have some effect on your voice, and your breathing, but if you are training properly and using good judgement, you can sing until very late in life and still sound good.
You shouldn't compare yourself to professionally-recorded singers because they often sing very differently than anyone singing live. Plus they have all sorts of recording tricks they use.
That's my two cents
Good luck!