That's so true even not only for Bitcoin but also for other altcoins. If a coin is good enough then Early investor will make huge profit. Although everyone can't afford to buy Bitcoin when price was low as they have to manage their livelihood true. But who have ability, i also recommended them to buy Bitcoin earlier. Bitcoin may can't give you 5-10x return like altcoins but Bitcoin is safe , secure and always best for investment. Thats why people recommended it
You are right actually, and one thing I really would like us to understand is that, FOMOing is a normal thing in crypto, almost every investor has sometime in the past fomoed in to a crypto investment, and even in the future, most investors will still at some point fomo into a crypto investment, and such investment could be bitcoin or any other altcoin, but just as you have said, it's actually very much better and safer to fomo into investing in bitcoin, than fomo into investing in some random altcoins.
When it comes to investing in bitcoin, it is advised that we should take our time and get a good price to enter, but when the market is going up steadily and rapidly like it does in a bull run, it's better to get in at any price else, you might just miss out on some potential profit, and let's say that after getting in, the price of bitcoin drops, just keep holding and dca, bitcoin will always rise again.