I'm not in a position to judge whether someone is right or wrong, as everyone's knowledge is different. But if they say it's too late to invest in Bitcoin now, let it be. It doesn't benefit me whether they invest or not, so why should I care.
It's not my job to convince someone to invest their money in Bitcoin. Just leave them be. At least, when the Bitcoin price is higher, they'll regret not investing, and realize they should have invested their money --- or not.
Well, you're actually not wrong, there is no point in wasting our time trying to convince others to make investments in Bitcoin or cryptocurrencies, because neither us or the market is going to benefit from that, it is just for their benefit, and if they are not ready to do it, just let them be, all we can do is tell them Bitcoin is good, and then ask them to do their own research if they are willing to make an investment and that's it.
Never be the person who forces someone to do something because if things go wrong later, you will be blamed for it, so it's better to make things clear beforehand and make sure you are clear and they won't have any point to blame you for.
You should share whatever knowledge you have with people when they ask about it, for example, if you are sitting in a group, and no one is talking about cryptocurrencies or showing confusion, then you don't need to bring it up, but if they are already talking about it, and some of them are confused about something and you know it, then you can go ahead and share your knowledge, and that's it, you don't need to give investment advice to anyone, and let them decide on their own if they actually want to do it or not.