Our chakras are not actually closed. Even if a single chakra would be actually and fully closed, we would be dead. And dead not just by body, but by soul. Assuming chakras as separate parts is not fully correct. It is a good model, but in reality they work in totality.
Instead, we are affected by energies that are limiting our real inner power which create the illusion of our chakras being closed. So, we need to deal with those specific energies in ways that are needed. Sometimes we erase them. Sometimes we simply purify our chakras.
I would assume that Gods created us without any mistakes, as perfect beings. And they gave us so-called free will. And our inability to use that free will properly by listening to the Gods until we would get necessary self-independence resulted in our own souls getting polluted by various energies that limited us. The enemy abused our own lack of knowledge. Abusing lack of knowledge can be seen as millions of examples in the real world every day. Just go to any state institution. Even there you will be filtered if you know the law or not. If you know it, you will get treatment according to the known law. If not, they will do everything in their power to abuse you.
Now let us get back to the chakras question. "Opening" all of them is not needed. You should focus on the one that causes most problems to you. Follow your own intuition and you will get there. Following your intuition basically means listening to the voice of the Gods. And mostly this is enough in the beginning phases.
There is no need to push yourself more than you actually can. The most important thing in this path is the ability to maintain long-term discipline. Everyone can do huge stuff in a matter of weeks. But here we are focusing on years, decades, even thousands of years. You need to make sure you are advancing in ways that Gods lead you to.
I do not imply any laziness here. What I imply is a healthy outlook. You need to see what you can do right now, follow the intuition and just advance at the pace you are able to keep. Nothing more, nothing less. Try finding the balance that works best for your own advancement.