1 is all you need, I think 2 is the best. There are times where your other gun may be out of service (I had to let loctite dry on my front sight the other day). And it’s not bad to have options. One really only needs one.
I think it’s funny because I think back on my first carry gun and I realize that’s probably the only gun I ever really needed… but I bought a few before I lost them in a boating accident.