No. It is not too late because there are many people who uses bitcoin who wanted also to invest but they have a question in their mind if it's too late. It's not yet too late because as long as bitcoin never stops, investment will never stop also. As long as there are users, there is bitcoin and if there's bitcoin, there will be an investment.
Yes it is not too late to buy the btc as already btc prices have started t climb and reached 7500$ and in coming days we can see it above 9k as well. So if you are a trader or short term investor investing now can be a fruitful as well to make some quick dollars for short time.
I don't think it is too late to invest in Bitcoin. It was considered too late for those who didn't buy and when it reached it's all time high. Or it could be late for someone who knew Bitcoin since it was a few bucks. For the people who have come to know it since an year or less than it, for all of these people right now is a great opportunity to get into it.