What is Christianity? Say, many Eastern Orthodox Christian Churches have considered the Western Christianity (so called Catholics and whatever came out of them — Protestants etc) to be schismatics and thus not Christian for almost 1000 years. Are they right? Wrong? why? Are they themselves united and uniform? Yes, no? Did you research that? Did you try to understand?
You’re somewhat right, however, I’d say that what is being viewed (or portrayed) as Christianity in the modern world is not relevant for it is not Christianity. Judging the tree by its fruits is a sure bet — not everyone (not every organization) calling themselves Christian is Christian.
And this has been the case for… well, for a lot longer than you’ve been around.
“Then if any man shall say unto you, Lo, here is Christ, or there; believe it not. For there shall arise false Christs, and false prophets, and shall shew great signs and wonders; insomuch that, if it were possible, they shall deceive the very elect. “