Is college necessary for acting?

College is important because you will be going up against people who have studied in auditions. Actors want to work with people they know are good, and you only get to be good is with practice and study. Most movie actors have studied. The best way to find dedicated, professional people is to start at the university level.
Bottom line, if you love acting, make it your business to know everything you can about it. That is the only way you will ever be the best, and only the best work. Luck is only practice and timing, so practice with the best while you wait and watch for your moment.
Break a leg!

If you go to school for acting you will gain 2 very important things: education and contacts.

Getting an education in acting has certainly been argued by theatre practioners over the years. Some say it is a waste of time, others will tell you it is absolutely imperative. My opinion is that it doesn't hurt to learn more about your craft before you get out there. In addition, schools can give you insights into the business of being an actor. Knowledge gives you confidence and confidence is a big part of success.

Networking applies to any profession including acting. You never know if the director you work with in class will become the next Spielberg. And if you continue a good working relationship, he/she just might call you to star in their next Broadway show or feature film.

Exactly, there's never a guarantee you will or can make a living as an Actor.

Nevertheless, should you get into a school such as Juilliard or Yale Drama or RADA (Royal Academy of Dramatic Arts in England)--you will have a much higher chance of being noticed a lot more.

Even if you do not manage to be accepted to those schools. New York training is often considered top of the line by film and television casting directors. All acting schools that offer college credits and degrees are by audition only.

Great actors continue to study throughout their careers. And you need to love it as there's often a chance you may never make a living wage doing it.

Now, I encourage you to do what you love and believe you will make it. That means, of course, you love each and every chance to act. Schooling, classes, etc.

Is college necessary? No. It helps, though if acting is 1) not paying well or at all. In many states, if you have a 4-year degree, you can be a Substitute Teacher and keep food on the table.