I think culinary school is good to make it easier to get to hospitality position, which is extremely hard without previous kitchen job.
I will say it from my own experience - It depends where you want to get to.
I started from zero. Literally zero.
I always loved cooking as a child, I was surprising my mother with recipes she still cannot cook, I experimented and watched tons of cooking tv shows.
I never thought I will get to hospitality until I've lost my job in a hotel and I was very, very desperate. I saw one sushi maker job in London and I applied. Few hours later I've got a call with a trial proposition.
I went there. Started to work. Worked hard. I cooked my ass off. First week I was portioning kilograms of pickled ginger into small, plastic containers, each portion 30 grams. After that week, when they saw I work hard no matter what job they give me, they allowed me to do basic sushi. And that's how in three months I've got up the line and could manage every section in the kitchen.
But it was only a small sushi shop.
After that, then, I went to one of Gordon Ramsay's restaurants, asking for a free stage.I felt in love with the food. And employers felt in love with my CV!
With that on my CV, I became a head chef in the next two years. I was working in a few high street kitchens in London.
Nothing. Absolutely NOTHING will give you as much experience as cooking by itself.
You just need to want to learn. You have to show them you want to learn, that you want to know more. You have to show up every day with a great attitude and LISTEN to what they want to teach you. No matter whether it's scrubbing the kitchen floor or making a veloute.
Of course, it depends on where you end up and what kind of chefs you have around you. I've met a lot of people with years of experience who knew nothing.
Do your research.
Read about things like mother sauces, sugar temperatures, knife techniques, basic cooking techniques, learn how to make basic french desserts (a lot of techniques, useful everywhere later on), how to make a proper stock, and I guarantee at one point you could be better than most people who despite the fact they have finished a fancy cooking school can't make a good hollandaise or anglaise without scrambling it.
Good luck!